Step 1: Divide the number into separate digits:
65637 => 6 5 6 3 7
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
6 to 5 = 1
5 to 6 = 1
6 to 3 = 3
3 to 7 = 4
7 to 6 = 1
Step 3: Combine the filters to a string:
1 1 3 4 1 = 11341