Across: A: A prime number
D: A across multiplied with the digit sum of D down
F: A prime number
G: A square number
H: A multiple of D across
J: A palindrome (a number that equals its reverse)
Down: A: A multiple of D down
B: If you are a purist, ignore this piece of information since you don't need it: B down is prime.
C: The reverse of C down is a multiple of the digit sum of F across.
D: The reverse of A across
E: If you are a purist, ignore this piece of information since you don't need it: all digits of E down are even.
I: A square number