The city is 385.8 sq mi (999.3 sq km ) in area . Hanoi is at an elevation of 7380 ft . The land area of the city is 11,609.91 km 2  (4,482.61 sq mi) . The water area of the city is 4.46 sq km  (1.72 sq mi) . +374 10 is the area code of Hanoi . This city is named after Confluence of Grand River and Gunnison River . Hanoi is the government of National Park Service . The density of  inhabitents in  the urban region of Hanoi is 4,800/km 2  (12,000/sq mi) . The population of the metro region is Populations (2019): 3,731,447 . The city Hanoi demonym is Barranquillero/a . The Hanoi citys' lowest elevation is 190 m  . The city has the postal code 130000 . 2,813/km 2  (7,290/sq mi) is the density of inhabitents in  the metro region of Hanoi . The density of  inhabitents in Hanoi is 5,300/km 2  (14,000/sq mi) . On March 6, 1836 (city) the city was incorporated . The mayor of Hanoi is Tang Liangzhi . The urban region is 14.0 sq mi (36 km 2 ) in area
1224 sq km  is the area of Hanoi