Step 1: Divide the number into separate digits:
56821 => 5 6 8 2 1
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
5 to 6 = 1
6 to 8 = 2
8 to 2 = 6
2 to 1 = 1
1 to 5 = 4
Step 3: Combine the filters to a string:
1 2 6 1 4 = 12614