About this number
(240) 366 is a landline based telephone number operated by At&T Local and is located in zip code 21770 in the city of Monrovia, Maryland, which is in Frederick County, and is in the South. It has a Number Planning Area (NPA - also known as an Area Code) of 240 and Network Numbering Exchange (NXX - also known as a prefix) of 366. It has an Operating Company Number (OCN) of 7421. A Common Language Location Identifier (CLLI) of MNRVMDMODS1. As well as a Local access and transport area (LATA) of 240. Zip code 21770 has a population of 5,164 as of the 2010 census.