To solve this Level 3 puzzle start with the clues in the first row, 15 and 5. Put their factors in the first column and top row, then work down the puzzle finding the factors of all of the clues. Every factor you write in the first column or top row must be a number from 1 to 12 and can only be used once in each place.

Now here is a little bit about the number 1046:

• 1046 is a composite number.
• Prime factorization: 1046 = 2 × 523
• The exponents in the prime factorization are 1 and 1. Adding one to each and multiplying we get (1 + 1)(1 + 1) = 2 × 2 = 4. Therefore 1046 has exactly 4 factors.
• Factors of 1046: 1, 2, 523, 1046
• Factor pairs: 1046 = 1 × 1046 or 2 × 523
• 1046 has no square factors that allow its square root to be simplified. √1046 ≈ 32.34192

1046 is also palindrome 626 in BASE 13 because 6(13²) + 2(13) + 6 (1) = 1046