1170 Factor Trees

1170 is one of those numbers with twenty-four factors. Why does it have so many? Because of its prime factorization. You can find a number’s prime factorization by making a factor tree. Here are eleven different factor trees for 1170. Each one of them produces the same prime factorization: 1170 = 2 × 3² × 5 × 13

  • 1170 is a composite number.
  • Prime factorization: 1170 = 2 × 3 × 3 × 5 × 13, which can be written 1170 = 2 × 3² × 5 × 13
  • The exponents in the prime factorization are 1, 2, 1, and 1. Adding one to each and multiplying we get (1 + 1)(2 + 1)(1 + 1)(1 + 1) = 2 × 3 × 2 × 2 = 24. Therefore 1170 has exactly 24 factors.
  • Factors of 1170: 1, 2, 3, 5, 6, 9, 10, 13, 15, 18, 26, 30, 39, 45, 65, 78, 90, 117, 130, 195, 234, 390, 585, 1170
  • Factor pairs: 1170 = 1 × 1170, 2 × 585, 3 × 390, 5 × 234, 6 × 195, 9 × 130, 10 × 117, 13 × 90, 15 × 78, 18 × 65, 26 × 45, or 30 × 39
  • Taking the factor pair with the largest square number factor, we get √1170 = (√9)(√130) = 3√130 ≈ 34.20526

33² +  9² = 1170
27² +  21² = 1170

1170 is also the hypotenuse of FOUR Pythagorean triples:
288-1134-1170 calculated from 27² –  21², 2(27)(21), 27² +  21²
450-1080-1170 which is (5-12-13) times 90
594-1008-1170 calculated from 2(33)( 9), 33² –  9², 33² +  9²
702-936-1170 which is (3-4-5) times 234

1170 is 102102 in BASE 4 because 4⁵ + 2(4³) +4² + 2(1) = 1170,
and it’s repdigit 2222 in BASE 8 because 2(8³ + 8² + 8¹ + 8⁰) = 2(585) = 1170

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1152 Will You See All the Prime Factors in This Factor Tree?

Will you see all the prime factors in this factor tree when all of the factors are the same color? You know how to count, but would you possibly not count one of the prime factors or possibly count one of them twice?

Is it easier to count the prime factors in the following factor trees?

If you happen to have two different colors of ink and/or pencils around when you make factor trees, they might be easier to read especially if the factored number has a lot of factors like 1152 does.

Here’s what I’ve learned about the number 1152:

  • 1152 is a composite number.
  • Prime factorization: 1152 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 3 × 3, which can be written 1152 = 2⁷ × 3²
  • The exponents in the prime factorization are 7 and 2. Adding one to each and multiplying we get (7 + 1)(2 + 1) = 8 × 3 = 24. Therefore 1152 has exactly 24 factors.
  • Factors of 1152: 1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 32, 36, 48, 64, 72, 96, 128, 144, 192, 288, 384, 576, 1152
  • Factor pairs: 1152 = 1 × 1152, 2 × 576, 3 × 384, 4 × 288, 6 × 192, 8 × 144, 9 × 128, 12 × 96, 16 × 72, 18 × 64, 24 × 48, or 32 × 36
  • Taking the factor pair with the largest square number factor, we get √1152 = (√576)(√2) = 24√2 ≈ 33.94112

The last two digits of 1152 are 52, a number divisible by 4, so 1152 can be evenly divided by 4.
1 + 1 + 5 + 2 = 9, so 1152 is divisible by 9.

It is so easy to tell if a number can be evenly divided by 4 or 9 AND it is so easy to divide by 4 or by 9. When I make a factor cake, I like to see if the current layer of the cake is divisible by 4 or by 9 before I check to see if it is divisible by a prime number.

From that cake, I can quickly tell that 1152 = 2⁷ × 3² by simply counting by 2’s to find the powers of 2 and 3. All the numbers being the same color doesn’t even slow me down.

I can also easily find the √1152 by taking the square root of everything on the outside of the cake:
√1152  = √(4·4) · (√4)(√9)(√2) = (4·2·3)√2 = 24√2

Since MOST square roots that can be simplified are divisible by 4, or by 9, or by both, this is a good strategy to find their square roots.

Here are some more facts about this number:

1152 is the sum of the fourteen prime numbers from 53 to 109,
and it is the sum of the twelve prime numbers from 71 to 127.

34² – 2² = 1152 so we are only 2² = 4 numbers away from the next perfect square.

1152 looks interesting when it is written in these bases:
It’s 800 in BASE 12 because 8(12²) = 1152,
242 in BASE 23 because 2(23²) + 4(23) + 2(1) = 1152
200 in BASE 24 because 2(24²) = 1152,
WW in BASE 35 (W is 32 base 10) because 32(35) + 32(1) = 32(36) = 1152, and
it’s W0 in BASE 36 because 32(36) = 1152

1150 Perfectly Symmetrical Factor Trees

Factor trees can look lovely if they have symmetrical branches. 1150 can make that kind of a tree:

The same number can also make a more disorderly-looking tree:

All of those trees are correct factor trees. And several more can still be made for the number 1150.

What else can I tell you about that number?

  • 1150 is a composite number.
  • Prime factorization: 1150 = 2 × 5 × 5 × 23, which can be written 1150 = 2 × 5² × 23
  • The exponents in the prime factorization are 1, 2, and 1. Adding one to each and multiplying we get (1 + 1)(2 + 1)(1 + 1) = 2 × 3 × 2 = 12. Therefore 1150 has exactly 12 factors.
  • Factors of 1150: 1, 2, 5, 10, 23, 25, 46, 50, 115, 230, 575, 1150
  • Factor pairs: 1150 = 1 × 1150, 2 × 575, 5 × 230, 10 × 115, 23 × 50, or 25 × 46,
  • Taking the factor pair with the largest square number factor, we get √1150 = (√25)(√46) = 5√46 ≈ 33.91165

1150 is the hypotenuse of two Pythagorean triples:
690-920-1150 which is (3-4-5) times 230
322-1104-1150 which is (7-24-25) times 46

1150 looks interesting when it is written in a couple of different bases:
It’s 3232 in BASE 7 because 3(7³) + 2(7²) + 3(7) + 2(1) = 1150
and 6A6 in BASE 13 (A is 10 base 10) because 6(13²) + 10(13) + 6(1) = 1150

1140 is the 18th Tetrahedral Number

1140 is the 18th tetrahedral number because it satisfies this formula:
(18)(18+1)(18+2)/6 = 1140

It is the 18th tetrahedral number because it is the sum of the first 18 triangular numbers:

Since 18 is an even number, 1140 is the sum of the first 9 EVEN squares.

If the 1140 tiny squares in that graphic were cubes, they could be stacked into a tower with either a triangular base or a square base. Then we would see the beauty of this tetrahedral number.

We can see the number 1140 as well as ALL the previous tetrahedral numbers on this portion of Pascal’s Triangle. (They are the green squares.):

1140 has its place as the 3rd number (as well as the 17th number) on the 20th row of Pascal’s triangle because of this next formula:

Here are some other facts about the number 1140:

  • 1140 is a composite number.
  • Prime factorization: 1140 = 2 × 2 × 3 × 5 × 19, which can be written 1140 = 2² × 3 × 5 × 19
  • The exponents in the prime factorization are 2, 1, 1, and 1. Adding one to each and multiplying we get (2 + 1)(1 + 1)(1 + 1)(1 + 1) = 2 × 3 × 2 × 2 = 24. Therefore 1140 has exactly 24 factors.
  • Factors of 1140: 1, 2, 3, 4, 5, 6, 10, 12, 15, 19, 20, 30, 38, 57, 60, 76, 95, 114, 190, 228, 285, 380, 570, 1140
  • Factor pairs: 1140 = 1 × 1140, 2 × 570, 3 × 380, 4 × 285, 5 × 228, 6 × 190, 10 × 114, 12 × 95, 15 × 76, 19 × 60, 20 × 57, or 30 × 38,
  • Taking the factor pair with the largest square number factor, we get √1140 = (√4)(√285) = 2√285 ≈ 33.76389

Here are some factor trees that use 11 of 1140’s factor pairs:

1140 is the sum of consecutive prime numbers two different ways:
179 + 181 + 191 + 193 + 197 + 199 = 1140,
569 + 571 = 1140

1140 is the hypotenuse of a Pythagorean triple:
684-912-1140 which is (3-4-5) times 228

1140 looks interesting when it is written in a couple other bases:
It’s palindrome 474 in BASE 16 because 4(16²) + 7(16) + 4(1) = 1140,
and it’s 330 in BASE 19 because 3(19²) + 3(19) = 3(19² + 19) = 3(19)(20) = 1140

1134 Some Likely Factor Trees

I could easily make nine factor trees for 1134 using different factor pairs of 1134. However, most people aren’t likely to begin a factor tree by first dividing 1134 by 14, 18, 21, or 27. Most people will want to start with a 1-digit divisor of 1134.

Most people will also use only one color of ink or pencil lead to make a factor tree.

Here are three of 1134’s factor trees that are much more likely to be made by the average person.

How easy is it to find all the prime factors in those one-color trees? You will probably think it is easier for some trees than others.

I think the tree in the middle is the easiest to read. All the prime factors are in the correct order and easy to distinguish from the composite factors in the tree. Although it is similar to using the cake method, I still like the cake method better.

Here are some facts about the number 1134:

  • 1134 is a composite number.
  • Prime factorization: 1134 = 2 × 3 × 3 × 3 × 3 × 7, which can be written 1134 = 2 × 3⁴ × 7
  • The exponents in the prime factorization are 1, 4 and 1. Adding one to each and multiplying we get (1 + 1)(4 + 1)(1 + 1) = 2 × 5 × 2 = 20. Therefore 1134 has exactly 20 factors.
  • Factors of 1134: 1, 2, 3, 6, 7, 9, 14, 18, 21, 27, 42, 54, 63, 81, 126, 162, 189, 378, 567, 1134
  • Factor pairs: 1134 = 1 × 1134, 2 × 567, 3 × 378, 6 × 189, 7 × 162, 9 × 126, 14 × 81, 18 × 63, 21 × 54, or 27 × 42
  • Taking the factor pair with the largest square number factor, we get √1134 = (√81)(√14) = 9√14 ≈ 33.67492

1134 is the sum of four consecutive prime numbers:
277 + 281 + 283 + 293 = 1134

1120 There’s Lots of Shade under These Factor Trees!

It’s hot this summer, but you can rest under the shade of some of 1120’s factor trees. Whether you want a tall tree or a wide one, these are only a few of the MANY possible ones you can choose. Every one of them gives you the same prime factors which are shown in pink here.

Here are some things I’ve learned about the number 1120:

  • 1120 is a composite number.
  • Prime factorization: 1120 = 2 × 2 × 2 × 2 × 2 × 5 × 7, which can be written 1120 = 2⁵ × 5 × 7
  • The exponents in the prime factorization are 5, 1, and 1. Adding one to each and multiplying we get (5 + 1)(1 + 1)(1 + 1) = 7 × 2 × 2 = 28. Therefore 1120 has exactly 28 factors.
  • Factors of 1120: 1, 2, 4, 5, 7, 8, 10, 14, 16, 20, 28, 32, 35, 40, 56, 70, 80, 112, 140, 160, 224, 280, 560, 1120
  • Factor pairs: 1120 = 1 × 1120, 2 × 560, 4 × 280, 5 × 224, 7 × 160, 8 × 140, 10 × 112, 14 × 80, 16 × 70, 20 × 56, 28 × 40, or 32 × 35
  • Taking the factor pair with the largest square number factor, we get √1120 = (√16)(√70) = 4√70 ≈ 33.4664

1120 is the sum of the twenty prime numbers from 17 to 101.
It is also the sum of these two consecutive primes:
557 + 563 = 1120

1120 is the hypotenuse of exactly one Pythagorean triple:
672-896-1120 which is (3-4-5) times 224

I like the way 1120 looks in these other bases:
It’s 1112111 in BASE 3 because 3⁶ + 3⁵ + 3⁴ + 2(3³) + 3² + 3  + 1 = 1120,
929 in BASE 11 because 9(11²) + 2(11) + 9(1) = 1120,
WW in BASE 34 (W is 32 base 10) because 32(34) + 32(1) = 32(35) = 1120,
and W0 in BASE 35 because 32(35) = 1120

1092 Predictable Factor Trees

A couple of years ago on Memorial Day weekend, we bought two peach trees from a local nursery. Those trees have grown bigger, and we will get some peaches this year. The smaller tree has lots of fruit growing on it and will need some attention because the branches will be too small to support the weight of all that fruit. The bigger tree has exactly one peach growing on it.

These factor trees for the number 1092 are a lot more predictable than those peach trees: No matter which of its factor pairs you use, you will always eventually get
2² × 3 × 7 × 13 = 1092.

Here are some more facts about 1092:

  • 1092 is a composite number.
  • Prime factorization: 1092 = 2 × 2 × 3 × 7 × 13, which can be written 1092 = 2² × 3 × 7 × 13
  • The exponents in the prime factorization are 2, 1, 1, and 1. Adding one to each and multiplying we get (2 + 1)(1 + 1)(1 + 1)(1 + 1) = 2 × 3 × 2 × 2 = 24. Therefore 1092 has exactly 24 factors.
  • Factors of 1092: 1, 2, 3, 4, 6, 7, 12, 13, 14, 21, 26, 28, 39, 42, 52, 78, 84, 91, 156, 182, 273, 364, 546, 1092
  • Factor pairs: 1092 = 1 × 1092, 2 × 546, 3 × 364, 4 × 273, 6 × 182, 7 × 156, 12 × 91, 13 × 84, 14 × 78, 21 × 52, 26 × 42, or 28 × 39
  • Taking the factor pair with the largest square number factor, we get √1092 = (√4)(√273) = 2√273 ≈ 33.04542

(12 × 13 × 14)/2 = 1092
Even though 1092 can claim that cool fact, it will actually make the next number a STAR!

1092 is the sum of the twelve prime numbers from 67 to 113:
67 + 71 + 73 + 79 + 83 + 89 + 97 + 101 + 103 + 107 + 109 + 113 = 1092

1092 has a lot of factors, but it is the hypotenuse of only one Pythagorean triple:
420-1008-1092 which is (5-12-13) times 84

Look how cool 1092 is in some other bases:

Not only does it use only 0’s and 1’s in base 2 but also in consecutive bases 3 and 4:
It’s 10001000100 in BASE 2 because 2¹º + 2⁶ + 2² = 1092,
1111110 in BASE 3 because 3⁶ + 3⁵ + 3⁴ + 3³ + 3² + 3¹ = 1092,
and 101010 in BASE 4 because  4⁵ + 4³ + 4¹ = 1092

I like the way it looks in consecutive bases 12 and 13:
It’s 770 in BASE 12, because 7(12² + 12) = 7(156) = 1092
and 660 in BASE 13 because 6(13² + 13) = 6(182) = 1092

And its repdigit 444 in BASE 16 because 4(16² + 16 + 1) = 1092

Some of these facts about 1092 were predictable and some were not, but I have enjoyed learning all of them and hope that you have too.

What’s Special About √1024?

What’s special about √1024? Is it because it and several counting numbers after it have square roots that can be simplified?

Perhaps.

Maybe it is interesting just because √1024 = 32, a whole number. The 5th root of 1024 = 4 and the 10th root of 1024 = 2, both whole numbers as well.

Those equations are true because 32² = 1024, 4⁵ = 1024, and 2¹⁰ = 1024.

Or perhaps 1024 is special because it is the smallest number that is a 10th power. (It is 2¹⁰.) The square root of a perfect 10th power is always a perfect 5th power. (32 = 2⁵ and is the smallest number that is a 5th power.)

1024 is also the smallest number with exactly 11 factors.

It is the smallest number whose factor tree has at least 10 leaves that are prime numbers. (They are the red leaves on the factor tree shown below.) It is possible to draw several other factor trees for 1024, but they will all have the number 2 appearing ten times.

What’s more, I noticed something about 1024 and some other multiples of 256: Where do multiples of 256 fall on the list of square roots that can be simplified?

  • 256 × 1 = 256 and 256 is the 100th number on this list of numbers whose square roots can be simplified.

1st 100 reducible square roots

  • 256 × 2 = 512. When we add the next 100 square roots that can be simplified, 512 is the 199th number on the list.

2nd 100 reducible square roots

  • Here are the third 100 square roots that can be simplified:

Reducible Square Roots 516-765

  • 256 × 3 = 768 didn’t quite make that list because it is the 301st number. Indeed, it is the first number on this list of the fourth 100 numbers whose square roots can be simplified.

  • 256 × 4 = 1024. That will be the first number on the 5th 100 square roots list!

It is interesting that those multiples of 256 have the 100th, the 199th, the 301st, and the 401st positions on the list. That is so close to the 100th, 200th, 300th, and 400th positions.

In case you couldn’t figure it out, the highlighted square roots are three or more consecutive numbers that appear on the list.

1024 is interesting for many other reasons. Here are a few of them:

(4-2)¹⁰ = 1024, making 1024 the 16th Friedman number.

I like to remember that 2¹⁰ = 1024, which is just a little bit more than a thousand. Likewise 2²⁰ = 1,048,576 which is about a million. 2³⁰ is about a billion, and 2⁴⁰ is about a trillion.

*******
As stated in the comments, Paula Beardell Krieg shared a related post with me. It takes exactly 1024 Legos to build this fabulous pyramidal fractal:

https://platform.twitter.com/widgets.js
1024 has so many factors that are divisible by 4 that it is a leg in NINE Pythagorean triples:
768-1024-1280 which is (3-4-5) times 256
1024-1920-2176 which is (8-15-17) times 128
1024-4032-4160 which is (16-63-65) times 64
1024-8160-8224 which is (32-255-257) times 32
1024-16368-16400 which is 16 times (64-1023-1025)
1024-32760-32776 which is 8 times (128-4095-4097)
1024-65532-65540 which is 4 times (256-16383-16385)
1024-131070-131074 which is 2 times (512-65535-65537),
and primitive 1024-262143-262145

Some of those triples can also be found because 1024 is the difference of two squares four different ways:
257² – 255² = 1024
130² – 126² = 1024
68² – 60² = 1024
40² – 24² = 1024
To find out which difference of two squares go with which triples, add the squares instead of subtracting and you’ll get the hypotenuse of the triple.
******

1024 looks interesting in some other bases:
It’s 1000000000 in BASE 2,
100000 in BASE 4,
2000 in BASE 8,
1357 in BASE 9,
484 in BASE 15,
400 in BASE 16,
169 in BASE 29,
144 in BASE 30,
121 in BASE 31, and
100 in BASE 32

  • 1024 is a composite number.
  • Prime factorization: 1024 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2, which can be written 1024 = 2¹⁰
  • The exponent in the prime factorization is 10. Adding one we get (10 + 1) = 11. Therefore 1024 has exactly 11 factors.
  • Factors of 1024: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024
  • Factor pairs: 1024 = 1 × 1024, 2 × 512, 4 × 256, 8 × 128, 16 × 64, or 32 × 32,
  • 1024 is a perfect square. √1024 = 32. It is also a perfect 5th power, and a perfect 10th power.

1020 A Week of Mystery

Sometimes changing things up a little is good. I decided to make a week’s worth of mystery level puzzles. The actual difficulty level will vary from puzzle to puzzle so give each one of them a try. If you think one is too easy or too difficult, the next one might not be. Here’s the first one:

Print the puzzles or type the solution in this excel file: 10-factors-1019-1027

Here’s a little bit about the number 1020:

It is only 8 more than 1008, the previous number that also had 24 factors. Here are a few of its MANY possible factor trees.

1020 is the sum of six consecutive prime numbers:
157 + 163 + 167 + 173 + 179 + 181 = 1020

1020 is the hypotenuse of four Pythagorean triples:
156-1008-1020 which is 12 times (13-84-85)
432-924-1020 which is 12 times (36-77-85)
480-900-1020 which is (8-15-17) times 60
612-816-1020 which is (3-4-5) times 204

1020 looks interesting when it is written using some different bases:
It’s 33330 in BASE 4 because 3(4⁴ + 4³ + 4² + 4¹) = 3(340) = 1020,
848 in BASE 11 because 8(11²) + 4(11) + 8(1) = 1020,
606 in BASE 13 because 6(13²) + 6(1) = 6(170) = 1020,
480 in BASE 15 because 4(15²) + 8(15) = 4(225 + 30) = 4(255) = 1020,
390 in BASE 17 because 3(17²) + 9(17) = 3(289 + 51) = 3(340) = 1020,
UU in BASE 33 (U is 30 base 10) because 30(33) + 30(1) = 30(34) = 1020, and
U0 in BASE 34 because 30(34) = 1020

  • 1020 is a composite number.
  • Prime factorization: 1020 = 2 × 2 × 3 × 5 × 17, which can be written 1020 = 2² × 3 × 5 × 17
  • The exponents in the prime factorization are 2, 1, 1, and 1. Adding one to each and multiplying we get (2 + 1)(1 + 1)(1 + 1)(1 + 1) = 2 × 3 × 2 × 2 = 24. Therefore 1020 has exactly 24 factors.
  • Factors of 1020: 1, 2, 3, 4, 5, 6, 10, 12, 15, 17, 20, 30, 34, 51, 60, 68, 85, 102, 170, 204, 255, 340, 510, 1020
  • Factor pairs: 1020 = 1 × 1020, 2 × 510, 3 × 340, 4 × 255, 5 × 204, 6 × 170, 10 × 102, 12 × 85, 15 × 68, 17 × 60, 20 × 51, or 30 × 34
  • Taking the factor pair with the largest square number factor, we get √1020 = (√4)(√255) = 2√255 ≈ 31.9374

A Forest of 1008 Factor Trees

The number 1008 has so many factors that I just had to make a forest of some of its MANY possible factor trees. 1008 has fifteen factor pairs. I’ve made a factor tree for every factor pair, except 1 × 1008. I’ll start off with these short, wide, beautiful trees that feature six of 1008’s factor pairs:

Notice that no matter what factor pair we use, each tree has the same prime factors that I have highlighted in red. Even this lean, thin very-easy-to-read tree uses those same prime factors:

Finally, here are eight more factor trees that begin with the other eight factor pairs for 1008. They aren’t as good-looking as all the trees above, but they still work as factor trees and help us find those same red prime factors for 1008:

Here are some other facts about the number 1008:

1008 is the sum of ten consecutive prime numbers:
79 + 83 + 89 + 97 + 101 + 103 + 107 + 109 + 113 + 127 = 1008

1008 looks interesting when written in some other bases:
It’s 33300 in BASE 4 because 3(4⁴) + 3(4³) + 3(4²) = 3(256 + 64 + 16) = 3(336) = 1008,
4400 in BASE 6 because 4(6³) + 4(6²) = 4(216 + 36) = 4(252) = 1008,
700 in BASE 12 because 7(12²) = 7(144) = 1008
SS in BASE 35 (S is 28 base 10) because 28(35) + 28(1) = 28(36) = 1008
S0 in BASE 36 because 28(36) = 1008

  • 1008 is a composite number.
  • Prime factorization: 1008 = 2 × 2 × 2 × 2 × 3 × 3 × 7, which can be written 1008 = 2⁴ × 3² × 7
  • The exponents in the prime factorization are 4, 2 and 1. Adding one to each and multiplying we get (4 + 1)(2 + 1)(1 + 1) = 5 × 3 × 2 = 30. Therefore 1008 has exactly 30 factors.
  • Factors of 1008: 1, 2, 3, 4, 6, 7, 8, 9, 12, 14, 16, 18, 21, 24, 28, 36, 42, 48, 56, 63, 72, 84, 112, 126, 144, 168, 252, 336, 504, 1008
  • Factor pairs: 1008 = 1 × 1008, 2 × 504, 3 × 336, 4 × 252, 6 × 168, 7 × 144, 8 × 126, 9 × 112, 12 × 84, 14 × 72, 16 × 63, 18 × 56, 21 × 48, 24 × 42, or 28 × 36
  • Taking the factor pair with the largest square number factor, we get √1008 = (√144)(√7) = 12√7 ≈ 31.74902