Step 1: Divide the number into separate digits:
68892 => 6 8 8 9 2
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
6 to 8 = 2
8 to 8 = 0
8 to 9 = 1
9 to 2 = 7
2 to 6 = 4
Step 3: Combine the filters to a string:
2 0 1 7 4 = 20174