No number in this puzzle starts with a zero, but zeros may occur within numbers.
Across: A: A palindrome and prime number.
C: The reverse of O across.
F: G across plus the digit sum of G across
G: The fourth power of the digit sum of L across.
I: A prime number.
J: Add M across to P across, multiply this sum with the digit sum of L across, and you get the same number as when you divide J across by A across.
K: Multiply the reverse of N across with itself, and the result is K across.
L: D down is a multiple of L across, and P across divided by the greatest common divisor of L across and P across is a cubic number.
M: Three times the digit sum of A across.
N: A prime number.
O: O across divided by N across equals L across plus 1.
P: G across multiplied with the digit product of L across.
Down: A: L across multiplied with G down.
B: G down + H down
D: A square number.
E: A palindrome.
G: G down is a multiple of the sum of P across and the reverse of K across.
H: A palindrome.