New York City is a big place with a lot of people and a multitude of businesses with multiple telephones and cellphones. Here is a list of the current area codes in use:
212 and 646 - Covers Manhattan.
718, 347 and 929 - Covers The Bronx, Brooklyn, Queens and Staten Island
917 - New York City Cell Phones
It has been announced that in the spring of 2017, a new area code, 332, will also cover Manhattan.