The United Mexican States, commonly known as Mexico, is a federal constitutional republic in North America. Covering almost 2 million square kilometres (over 760,000 sq mi), Mexico is the fifth-largest country in the Americas by total area and the 14th largest independent nation in the world. With an estimated population of 111 million, it is the 11th most populous country and the most populous Hispanophone country on earth. Mexico is a federation comprising thirty-one states and a Federal District, the capital city. <br/> As a regional power, and since 1994 the first Latin American member of the Organisation for Economic Co-operation and Development (OECD), Mexico is firmly established as an upper middle-income country, and is considered a newly industrialized country and an emerging power. It has the 13th largest nominal GDP and the 11th largest by purchasing power parity. Mexico boasts a long tradition in the arts, renowned cuisine, and culture, as it ranks fifth in the world and first in the Americas with 29 UNESCO World Heritage Sites.