Step 1: Divide the number into separate digits:
56470 => 5 6 4 7 0
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
5 to 6 = 1
6 to 4 = 2
4 to 7 = 3
7 to 0 = 7
0 to 5 = 5
Step 3: Combine the filters to a string:
1 2 3 7 5 = 12375