No zeros occur in this puzzle.

Across:
A: A quartic number.
C: A across plus A down.
E: A prime number.
G: A across multiply A down.
I: J across divided by the digit sum of A down.
J: G across multiplied by E across and the cube root of C across.
M: Reverse of L down.
N: A palindrome.
P: A palindrome.
R: A multiple of Z across.
S: A palindrome.
U: U down multiplied by Y across muliplied by the digit sum of O down.
V: Has the same digit sum as W down.
X: A prime number.
Y: A prime number.
Z: A non-prime number.

Down:
A: A prime number.
B: A palindrome.
D: Has the same digit sum as G across.
E: A palindrome.
F: A quintic.
H: Subtract M across from J across.
K: A prime number.
L: Has the same digit sum as X across.
N: O down multiplied by V across.
O: A non-prime number.
Q: A prime number.
R: A multiple of the reverse of F down.
S: A square number.
T: A palindrome.
U: X across multiplied by the digit sum of Q down.
W: Z across multiplied by the digit sum of O down.