No zeros occur in this puzzle.
A: the digit sum of A across equals E across plus the product of E across's digits.
C: a palindrome.
E: a palindrome and prime number.
G: G across divided by M down is a cubic number.
H: a prime number.
I: this prime number equals the sum of J down and C down.
K: a palindrome.
L: L across divided by J down is a square number.
N: F down divided by N across is a palindrome.
O: this palindrome is a multiple of E across.
B: a palindrome.
C: divide G down by G across and calculate the square root of the result, and you get a divisor of C down.
D: a multiple of E across.
E: I across + F down.
F: a cubic number.
G: a multiple of G across.
J: C down - 1.
M: the product of the digits of M down equals A across.