Step 1: Divide the number into separate digits:
44297 => 4 4 2 9 7
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
4 to 4 => 0
4 to 2 => 2
2 to 9 => 7
9 to 7 => 2
7 to 4 => 3
Step 3: Convert distances to codes (0=E[qual],
1 & 9 = C[onsecutive], 2-8 = N[one]):
0 => E
2 => N
7 => N
2 => N
3 => N
Step 4: Combine the filters to a string:
E N N N N = ENNNN