Step 1: Divide the number into separate digits:
19452 => 1 9 4 5 2
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
1 to 9 = 8
9 to 4 = 5
4 to 5 = 1
5 to 2 = 3
2 to 1 = 1
Step 3: Combine the filters to a string:
8 5 1 3 1 = 85131