Step 1: Divide the number into separate digits:
28092 => 2 8 0 9 2
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
2 to 8 = 6
8 to 0 = 8
0 to 9 = 9
9 to 2 = 7
2 to 2 = 0
Step 3: Combine the filters to a string:
6 8 9 7 0 = 68970