Here’s a neat number curiosity that you may find interesting.
Choose any number (preferably, a larger one). For example,
Write down the number of even digits, odd digits and the number of digits of the number you selected respectively:
8 11 19
Concatenate the three numbers:
Perform the procedure described above to the concatenated number:
1 4 5
Do it once again:
1 2 3
Now, if you do it again, it’ll loop back to 123. Hence, you will end up getting 123 regardless of which number you start with.