Let the digits of our 8-digit palindrome n be d1d2d3d4d4d3d2d1. Then the palindrome has the form
n=10000001⋅d1+1000010⋅d2+100100⋅d3+11000⋅d4.
Such n cannot be prime because gcd(10000001,1000010,100100,11000)=11.
So there are NO 8-digit prime palindromes. (However, there are prime palindromes with an odd number of digits, e.g. 101101, 1030110301, 9868998689, 98010899801089.)
The correct answer is 0.