Step 1: Divide the number into separate digits:
25734 => 2 5 7 3 4
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
2 to 5 = 3
5 to 7 = 2
7 to 3 = 4
3 to 4 = 1
4 to 2 = 2
Step 3: Combine the filters to a string:
3 2 4 1 2 = 32412