title: Johannesburg
context: 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).
question: How large is Johannesburg's population?
answers: 4,434,827