Step 1: Divide the number into separate digits:
27041 => 2 7 0 4 1
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
2 to 7 = 5
7 to 0 = 7
0 to 4 = 4
4 to 1 = 3
1 to 2 = 1
Step 3: Combine the filters to a string:
5 7 4 3 1 = 57431