I'm always wondering why we don't note down the base (10) when we name those numbers. There can be lots of others similars properties in small bases and all the "magic" properties of such numbers are just specific to base 10, there's nothing specific about 10 it's only what a lot of humans use
If almost all times you refer to a number is base 10, it is very redundant to mention it every time.
The "Kaprekar's routine" page [0] is more informative, covers other bases.