Step 1: Divide the number into separate digits:
37274 => 3 7 2 7 4
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
3 to 7 = 4
7 to 2 = 5
2 to 7 = 5
7 to 4 = 3
4 to 3 = 1
Step 3: Combine the filters to a string:
4 5 5 3 1 = 45531