Step 1: Divide the number into separate digits:
43930 => 4 3 9 3 0
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
4 to 3 = 1
3 to 9 = 6
9 to 3 = 6
3 to 0 = 3
0 to 4 = 4
Step 3: Combine the filters to a string:
1 6 6 3 4 = 16634