Area Code 331-777 located in DOWNERS GROVE, DUPAGE, IL, more detail is as below. Place NPA (Numbering Plan Area) : 331 NXX (Local Number Prefix) : 777 City : DOWNERS GROVE County : DUPAGE State : IL (Illinois) NXX Use Type : Landline NXX Intro Version : 9/22/2010 FIPS (Federal Information Processing Standards) : 17043 LATA (Local Access Transport Area) : 358 Rate Center : DOWNERSGRV ZIP Code Count : 0 ZIP Code Frequency : 0 ZIP Code : 60516 Other Information NPANXX : 331777 County Population : 0 MSA CBSA (Core Based Statistical Area) : Chicago-Naperville-Joliet, IL-IN-WI MSA CBSA Code (Core Based Statistical Area) : 16980 Time Zone : Central (GMT -06:00) Observes Daylight Saving Time : Yes Overlay : L Company : CYGNUS TELECOMMUNICATIONS CORPORATION - IL OCN (Operating Company Number) : 161F Coverage Area Name : DOWNERS GROVE Latitude : 41.7930 Longitude : -88.0001 ‹ previous : 331-725 next › : 331-803 Telephone Number List 331-777-0000 ~ 331-777-9999