No zeros occur in this puzzle.

**Across**:

**A**: N across + E across.

**E**: a cubic number.

**F**: the reverse of F across is a prime number.

**H**: I across + K down.

**I**: subtract D down from I across, and the result is a square number.

**J**: a prime number.

**L**: all digits of L across are the same.

**N**: subtract L across from A across and read the result backwards, and you get N across.

**Down**:

**A**: D down multiplied with E across.

**B**: a square number.

**C**: another square number.

**D**: a prime number.

**G**: D down multiplied with the reverse of I across.

**K**: I across - D down.

**L**: a palindrome.

**M**: a prime number.