Step 1: Divide the number into separate digits:
61094 => 6 1 0 9 4
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
6 to 1 = 5
1 to 0 = 1
0 to 9 = 9
9 to 4 = 5
4 to 6 = 2
Step 3: Combine the filters to a string:
5 1 9 5 2 = 51952