Step 1: Divide the number into separate digits:
57869 => 5 7 8 6 9
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
5 to 7 = 2
7 to 8 = 1
8 to 6 = 2
6 to 9 = 3
9 to 5 = 4
Step 3: Combine the filters to a string:
2 1 2 3 4 = 21234