emirp

noun

1. A prime number that becomes a different prime when its decimal digits (or digits in some specified other base) are reversed.

   “The sequence of emirps begins: 13, 17, 31, 37, 71, 73, 79, 97, 107, ...”

   “The first few emirps in base 12 (using the convention T for ten and E for eleven) are: 15, 51, 57, 5E, 75, E5, 107, ...”

   “Therefore we do not yet know whether the general emirps go on forever or whether they too eventually end with a largest emirp of all.”