Step 1: Divide the number into separate digits:
43789 => 4 3 7 8 9
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
4 to 3 = 1
3 to 7 = 4
7 to 8 = 1
8 to 9 = 1
9 to 4 = 5
Step 3: Combine the filters to a string:
1 4 1 1 5 = 14115