The set of two-digit primes is {11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97}
Of that list, the following primes are mirror images of each other 13 and 31 17 and 71 37 and 73 79 and 97 Note: we ignore 11 since 11 flips to 11 which is not distinct from its original
If you're looking for the largest prime of this form, then its 97 If you're looking for the largest gap, then subtract each pair 31-13 = 18 71-17 = 54 73-37 = 36 97-79 = 18 We see that 71 and 17 have the largest gap
The digits cannot be 2, 4, 6, 5, 8, because those numbers in the one's place do not make a prime number. of the numbers 1, 3, 7, 9, and largest is 97, and 79 is also a prime number, so the answer is 97
