Step 1: Divide the number into separate digits:
16868 => 1 6 8 6 8
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
1 to 6 = 5
6 to 8 = 2
8 to 6 = 2
6 to 8 = 2
8 to 1 = 7
Step 3: Combine the filters to a string:
5 2 2 2 7 = 52227