Step 1: Divide the number into separate digits:
14211 => 1 4 2 1 1
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
1 to 4 = 3
4 to 2 = 2
2 to 1 = 1
1 to 1 = 0
1 to 1 = 0
Step 3: Combine the filters to a string:
3 2 1 0 0 = 32100