The most common and most likely answer to this crossword clue is the 4 plus 5 letter word AREA CODES
I've seen this crossword clue in The Guardian
A
R
E
A
C
O
D
E
S
More clues leading to the result AREA CODES
Buddy explains!
The straight part
We know that "Some of the cell numbers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case some of the cell numbers = area codes.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.