If you just want to identify those duplicated numbers (with a count) then
COUNTIF() can do it for you.
Assume the first column is A and the other column is C with rows used from 2
to 234,
in the first cell next to a phone number in column A put this formula
(assume it's on row 2), so this goes into B2:
=COUNTIF(A2,$C$2:$C$234)
and then fill that down in column B as far as your numbers in it goes. It
will give you a count of number of times each number in A appears in C.