Palindromes and Anagrams in TOTP Codes

This morning, I entered yet another of those six digit TOTP codes to log into an online service. One thing that I always find interesting is when the second half of the code is similar to the first half, like say 675567 . My curiosity got the best of me and I just had to know how often that happens. The interesting cases would be a palindrome (eg. 123321 ), a repetition (eg. 123123 ), and an…