Step 1: Divide the number into separate digits:
85307 => 8 5 3 0 7
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
8 to 5 = 3
5 to 3 = 2
3 to 0 = 3
0 to 7 = 7
7 to 8 = 1
Step 3: Combine the filters to a string:
3 2 3 7 1 = 32371