Step 1: Divide the number into separate digits:
57431 => 5 7 4 3 1
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
5 to 7 = 2
7 to 4 = 3
4 to 3 = 1
3 to 1 = 2
1 to 5 = 4
Step 3: Combine the filters to a string:
2 3 1 2 4 = 23124