query: How large is Johannesburg's population?
passage: Johannesburg
The metropolis is an alpha global city as listed by the Globalization and World Cities Research Network. In 2011, the population of the city of Johannesburg was 4,434,827, making it the most populous city in South Africa.[4] In the same year, the population of Johannesburg's urban agglomeration was put at 7,860,781.[5] The land area of the municipal city (1,645km2 (635sqmi)) is large in comparison with those of other major cities, resulting in a moderate population density of 2,364/km2 (6,120/sqmi).
passage: Suburbs of Johannesburg
The southern suburbs, located in Regions 9, 10, and 11, extend to the south of the inner city, and are somewhat isolated from the rest of Johannesburg. On a map, the southern suburbs appear to hang down from the border of Soweto and Johannesburg South. It is about 40 kilometres south of the inner city. It is actually the most isolated, least integrated area of Johannesburg, with its east, west, and southern boundaries also forming Johannesburg proper's boundaries in the area. It is diagonally traversed by the N1, with the N12 running along its northern border.