Step 1: Divide the number into separate digits:
41661 => 4 1 6 6 1
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
4 to 1 = 3
1 to 6 = 5
6 to 6 = 0
6 to 1 = 5
1 to 4 = 3
Step 3: Combine the filters to a string:
3 5 0 5 3 = 35053