Brazil, officially the Federative Republic of Brazil, is the largest and easternmost country in South America and Latin America. It is the world's fifth-largest country by area and one of the most populated countries. Its capital is Brasília, and its most populous city is São Paulo. Brazil is a federation composed of 26 states and a Federal District. It is the only country in the Americas where Portuguese is an official language. Brazil is among the world's most multicultural and ethnically diverse nations, due to over a century of mass immigration from around the world.