Step 1: Divide the number into separate digits:
2833 => 2 8 3 3
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
2 to 8 = 6
8 to 3 = 5
3 to 3 = 0
3 to 2 = 1
Step 3: Combine the filters to a string:
6 5 0 1 = 6501