ACROSS A - A-down multiplied by the square of the reverse of A-down
G - J-across + square number
H - a square number
I - A-across - D-down
J - a multiple of R-across
K - odd, and its digit sum is a prime number
M - digit product of I-across
O - square root of the digit product of E-down
P - a cubic number
Q - a prime number
R - a prime number
DOWN A - a prime number
B - palindrome
C - palindrome
D - palindrome
E - multiple of N-down
F - multiple of A-down
I - multiple of L-down
L - palindrome
N - prime number