Step 1: Divide the number into separate digits:
73479 => 7 3 4 7 9
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
7 to 3 = 4
3 to 4 = 1
4 to 7 = 3
7 to 9 = 2
9 to 7 = 2
Step 3: Combine the filters to a string:
4 1 3 2 2 = 41322