Step 1: Divide the number into separate digits:
84186 => 8 4 1 8 6
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
8 to 4 = 4
4 to 1 = 3
1 to 8 = 7
8 to 6 = 2
6 to 8 = 2
Step 3: Combine the filters to a string:
4 3 7 2 2 = 43722