Step 1: Divide the number into separate digits:
46912 => 4 6 9 1 2
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
4 to 6 = 2
6 to 9 = 3
9 to 1 = 8
1 to 2 = 1
2 to 4 = 2
Step 3: Combine the filters to a string:
2 3 8 1 2 = 23812