Rio de Janeiro (Brazil) is 26 times larger than Oklahoma City.
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: 1,682 km2 calculated
Oklahoma City is the capital and largest city of the U.S. state of Oklahoma. The county seat of Oklahoma County, the city ranks 27th among United States cities in population. The population grew following the 2010 Census, with the population estimated to have increased to 610,613 as of July 2013. Wikipedia