Step 1: Divide the number into separate digits:
89646 => 8 9 6 4 6
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
8 to 9 = 1
9 to 6 = 3
6 to 4 = 2
4 to 6 = 2
6 to 8 = 2
Step 3: Combine the filters to a string:
1 3 2 2 2 = 13222