No zeros occur in this puzzle.

**Across**:

**A**: B down multiplied with H across.

**D**: A across + F down.

**E**: a prime number.

**G**: a cubic number.

**H**: take E across, subtract one from each digit, and the result is H across.

**I**: the first digit equals the digit sum of A across, while the second digit equals the digit sum of F down.

**K**: A across multiplied with the product of all digits of H across.

**M**: the greatest common divisor of M across and L down is greater than H across.

**Down**:

**A**: has the same digit sum as G across.

**B**: the digit sum of H across multiplied with H across.

**C**: a palindrome.

**D**: G across squared.

**F**: this square number equals H across multiplied with G across.

**J**: the reverse of L down.

**K**: a prime number.

**L**: E across multiplied with the digit sum of H across.