Step 1: Divide the number into separate digits:
51280 => 5 1 2 8 0
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
5 to 1 = 4
1 to 2 = 1
2 to 8 = 6
8 to 0 = 8
0 to 5 = 5
Step 3: Combine the filters to a string:
4 1 6 8 5 = 41685