Step 1: Divide the number into separate digits:
6183 => 6 1 8 3
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
6 to 1 = 5
1 to 8 = 7
8 to 3 = 5
3 to 6 = 3
Step 3: Combine the filters to a string:
5 7 5 3 = 5753