Step 1: Divide the number into separate digits:
76730 => 7 6 7 3 0
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
7 to 6 = 1
6 to 7 = 1
7 to 3 = 4
3 to 0 = 3
0 to 7 = 7
Step 3: Combine the filters to a string:
1 1 4 3 7 = 11437