Step 1: Divide the number into separate digits:
25224 => 2 5 2 2 4
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
2 to 5 = 3
5 to 2 = 3
2 to 2 = 0
2 to 4 = 2
4 to 2 = 2
Step 3: Combine the filters to a string:
3 3 0 2 2 = 33022