Step 1: Divide the number into separate digits:
57087 => 5 7 0 8 7
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
5 to 7 = 2
7 to 0 = 7
0 to 8 = 8
8 to 7 = 1
7 to 5 = 2
Step 3: Combine the filters to a string:
2 7 8 1 2 = 27812