Step 1: Divide the number into separate digits:
71893 => 7 1 8 9 3
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
7 to 1 = 6
1 to 8 = 7
8 to 9 = 1
9 to 3 = 6
3 to 7 = 4
Step 3: Combine the filters to a string:
6 7 1 6 4 = 67164