17, 23 and 71 are prime numbers because they have only two factors but 32 is a composite number because it has more than two factors.
About 32%
13 17 31 37 71 73 79 97
71 and 73 are twin primes.
They are called palindromic primes
There are 25 primes between 1 and 100: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, and 97.
Permutation primes are primes that have digits that can be rearranged with every possible rearrangement being a prime. Some examples of permutation prime sets are {13, 31}, {17, 71}, {79, 97}, {113, 131, 311}, and {337, 373, 733}.
They are: 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79
2 3 5 7 11 13 17 31 37 71 73 79 97
11 13, 31 17, 71 37, 73 79, 97
32 + x = 71 32 - 32 + x = 71 - 32 x = 39
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97
504 = 23 x 32 x 71