The lowest elevation of Hanoi is 7 ft . 35°50′08″N 51°00′37″E﻿ / ﻿35.83556°N 51.01028°E are the coordinates of the city. . The city is 47.84 sq mi (123.90 km 2 ) in area . Hanoi is at an elevation of 0 meters . The population of the metro region is Population (2019): 2,700,000 . 464.71/km 2  (1,203.6/sq mi) is the density of residents in  the urban region of Hanoi . The city water area is 21 km 2  (8 sq mi) . The city was incorporated in February 17, 1909 . The land area of the city is 314.95 sq mi (815.72 km 2 ) . The postal code of the city is 34000 to 34990 . The highest elevation of Hanoi is 241.9 m (793.6 ft) . The demonym of the city Hanoi is Catanesi . The density of  residents in  the metro region of Hanoi is 2,813/km 2  (7,290/sq mi) . Hanoi is named for Christopher Columbus . The density of  inhabitents in Hanoi is 2,700/km 2  (7,000/sq mi) . The urban region is Area: 713 km2 (275 sq mi) in area . Ravinder Bhalla (term ends December 31, 2021) is the mayor of Hanoi
More than 47 sq mi area of the city Hanoi is land