A trimorphic number is a positive integer whose cube ends with the number itself in decimal notation. Zero is excluded here.
The first few trimorphic numbers are: 4, 5, 6, 9, 24, 25, 49, 51, 75, 76, 99, …
60 of the first one million positive integers are trimorphic.
Learn more about trimorphic numbers on wikipedia.
See other features.