Bolivia, officially known as the Plurinational State of Bolivia, is a landlocked country located in western-central South America. The capital is Sucre while the seat of government is located in La Paz. The largest city and principal economic and financial center is Santa Cruz de la Sierra, located on the Llanos Orientales (Tropical lowlands) a mostly flat region in the East of Bolivia. It is constitutionally a unitary state, divided into nine departments. Its geography varies from the peaks of the Andes in the West, to the Eastern Lowlands, situated within the Amazon Basin. It is bordered to the north and east by Brazil, to the southeast by Paraguay, to the south by Argentina, to the southwest by Chile, and to the northwest by Peru. One-third of the country is within the Andean mountain range. With 1,098,581 km2 (424,164 sq mi) of area, Bolivia is the 5th largest country in South America and the 27th largest in the world. The country's population, estimated at 11 million, is multiethnic, including Amerindians, Mestizos, Europeans, Asians and Africans. The racial and social segregation that arose from Spanish colonialism has continued to the modern era. Spanish is the official and predominant language, although 36 indigenous languages also have official status, of which the most commonly spoken are Guarani, Aymara and Quechua languages.