Across: A: The digit sum of C down multiplied with A down.
C: A prime number.
D: The digit sum of E down.
G: C down multiplied with A across and the digit sum of A down divided by the digit sum of F down.

Down: A: A prime number.
B: The reverse of D across.
C: C down is both a cubic number and a square number.
E: A palindrome.
F: G across is a multiple of F down.