Step 1: Divide the number into separate digits:
72337 => 7 2 3 3 7
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
7 to 2 = 5
2 to 3 = 1
3 to 3 = 0
3 to 7 = 4
7 to 7 = 0
Step 3: Combine the filters to a string:
5 1 0 4 0 = 51040