Step 1: Divide the number into separate digits:
81716 => 8 1 7 1 6
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
8 to 1 = 7
1 to 7 = 6
7 to 1 = 6
1 to 6 = 5
6 to 8 = 2
Step 3: Combine the filters to a string:
7 6 6 5 2 = 76652