Area Code +1-301-(2170000...2179999) located in Rockville, Maryland (MD), more detail is as below. Place International Dialing Code : 1 International Prefix : 011 National Prefix : 1 National Destination Code : 301 Subscriber Number From : 2170000 Subscriber Number To : 2179999 National Destination Code Length : 3 Uses National Destination Code : Yes National Significant Number Length : 10 Number Type : G (Geographic Land Line, Fixed Line) Carrier Name : VERIZON MARYLAND INC Click here to buy United States Area Code Database Other Information Language Code : en (English) Country Number : 840 (United States) Country Code : US (United States) Region Code : MD Region Name : Maryland City : Rockville Timezone : America/New_York Coordinated Universal Time : -05:00 Daylight Saving Time : Yes National Significant Number Minimum Length : 10 Latitude : 39.0900 Longitude : -77.1600 ‹ previous : +1-301-(2160000...2169999) next › : +1-301-(2180000...2189999) Dialling Instructions For trunk calls: 0 301 2170000 (Trunk Code + National Destination Code + Subscriber Number) For international calls: 011 1 301 2170000 (International Prefix + International Dailing Code +National Destination Code + Subscriber Number) Telephone Number List 2170000 ~ 2179999 (Count: 10,000) Example: +1-301-2170000 / 0111-301-2170000 (1301-2170000 / 1-301-2170000) +1-301-2170001 / 0111-301-2170001 (1301-2170001 / 1-301-2170001) +1-301-2170002 / 0111-301-2170002 (1301-2170002 / 1-301-2170002) +1-301-2170003 / 0111-301-2170003 (1301-2170003 / 1-301-2170003) +1-301-2170004 / 0111-301-2170004 (1301-2170004 / 1-301-2170004) ...+1-301-xxxxxxx / 0111-301-xxxxxxx (1301-xxxxxxx / 1-301-xxxxxxx) ...+1-301-2179995 / 0111-301-2179995 (1301-2179995 / 1-301-2179995) +1-301-2179996 / 0111-301-2179996 (1301-2179996 / 1-301-2179996) +1-301-2179997 / 0111-301-2179997 (1301-2179997 / 1-301-2179997) +1-301-2179998 / 0111-301-2179998 (1301-2179998 / 1-301-2179998) +1-301-2179999 / 0111-301-2179999 (1301-2179999 / 1-301-2179999)