Step 1: Divide the number into separate digits:
69941 => 6 9 9 4 1
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
6 to 9 = 3
9 to 9 = 0
9 to 4 = 5
4 to 1 = 3
1 to 6 = 5
Step 3: Combine the filters to a string:
3 0 5 3 5 = 30535