A number n such that the last digits of n^3 are the same as n. 49 is trimorphic since 49^3 = 117649. The first few are 1, 4, 5, 6, 9, 24, 25, 49, 51, 75, 76, 99, 125, 249, 251, 375, 376, 499, ... (OEIS A033819).

automorphic number | narcissistic number | super-d number