Step 1: Divide the number into separate digits:
72858 => 7 2 8 5 8
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
7 to 2 = 5
2 to 8 = 6
8 to 5 = 3
5 to 8 = 3
8 to 7 = 1
Step 3: Combine the filters to a string:
5 6 3 3 1 = 56331