Chad, officially the Republic of Chad, is a country in Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon to the southwest, Nigeria to the southwest, and Niger to the west. Chad has a population of 20 million, of which 1.6 million live in the capital and largest city of N'Djamena. With a total area of around 1,300,000 km2 (500,000 sq mi), Chad is the fifth-largest country in Africa and the twentieth largest nation by area.