Step 1: Divide the number into separate digits:
78993 => 7 8 9 9 3
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
7 to 8 = 1
8 to 9 = 1
9 to 9 = 0
9 to 3 = 6
3 to 7 = 4
Step 3: Combine the filters to a string:
1 1 0 6 4 = 11064