In base twelve, and in base eight, "15" is a prime, and so is its 'reversal' "51".

There are many more prime pairs such as 15 and 51 (base eight or twelve) in an odd-number base than in an even-number base: in an even-number base any prime beginning with an even digit cannot be a prime when it is reversed.

Here (for example) is a list of some primes in base eleven which have prime reversals:

(T stands for ten in base eleven)

12, 21 | 16, 61 | 18, 81 | 27, 72 |

29, 92 | 34, 43 | 3T, T3 | 49, 94 |

56, 65 | 67, 76 | 89, 98 | 9T, T9 |

The pdf version of this page continues the theme, using two-way notation and the DSGB symbols for ten and eleven.