True. However, this problem can be formulated in other bases, and yield results of similar (in)significance. For example, for 4-digit numbers in base-9 there ar

True. However, this problem can be formulated in other bases, and yield results of similar (in)significance. For example, for 4-digit numbers in base-9 there are apparently just 2 cycles: 7252 → 5254 → 3076 → 7252 and 7072 → 7432 → 5074 → 7072.