Rio de Janeiro (Brazil) is 744 times larger than Manhattan (NYC borough).
Rio de Janeiro is one of the 27 states of Brazil. It has the third largest economy of Brazil, with the largest being that of the state of São Paulo, and the second being that of Minas Gerais. The state of Rio de Janeiro is located within the Brazilian geopolitical region classified as the Southeast. Wikipedia
Area: 59 km2 calculated
Manhattan is the most densely populated of the five boroughs of New York City. The borough is coterminous with New York County, an original county of the U.S. state of New York. Wikipedia