Step 1: Divide the number into separate digits:
41175 => 4 1 1 7 5
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
4 to 1 = 3
1 to 1 = 0
1 to 7 = 6
7 to 5 = 2
5 to 4 = 1
Step 3: Combine the filters to a string:
3 0 6 2 1 = 30621