Step 1: Divide the number into separate digits:
71749 => 7 1 7 4 9
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
7 to 1 = 6
1 to 7 = 6
7 to 4 = 3
4 to 9 = 5
9 to 7 = 2
Step 3: Combine the filters to a string:
6 6 3 5 2 = 66352