Step 1: Divide the number into separate digits:
17973 => 1 7 9 7 3
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
1 to 7 = 6
7 to 9 = 2
9 to 7 = 2
7 to 3 = 4
3 to 1 = 2
Step 3: Combine the filters to a string:
6 2 2 4 2 = 62242