Step 1: Divide the number into separate digits:
59540 => 5 9 5 4 0
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
5 to 9 = 4
9 to 5 = 4
5 to 4 = 1
4 to 0 = 4
0 to 5 = 5
Step 3: Combine the filters to a string:
4 4 1 4 5 = 44145