Step 1: Divide the number into separate digits:
04676 => 0 4 6 7 6
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
0 to 4 = 4
4 to 6 = 2
6 to 7 = 1
7 to 6 = 1
6 to 0 = 6
Step 3: Combine the filters to a string:
4 2 1 1 6 = 42116