Step 1: Divide the number into separate digits:
63742 => 6 3 7 4 2
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
6 to 3 = 3
3 to 7 = 4
7 to 4 = 3
4 to 2 = 2
2 to 6 = 4
Step 3: Combine the filters to a string:
3 4 3 2 4 = 34324