Step 1: Divide the number into separate digits:
62027 => 6 2 0 2 7
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
6 to 2 => 4
2 to 0 => 2
0 to 2 => 2
2 to 7 => 5
7 to 6 => 1
Step 3: Convert distances to codes (0=E[qual],
1 & 9 = C[onsecutive], 2-8 = N[one]):
4 => N
2 => N
2 => N
5 => N
1 => C
Step 4: Combine the filters to a string:
N N N N C = NNNNC