Reunion Business Directory: REU is the ISO 3 alphabet country code of Reunion. Currency of Reunion is €, which has a short code of EUR. Capital of Reunion is Saint-denis. Reunion has the population of 883247 and approximate area is 2512.00 square kilometers (or approx. 1560.9568 square miles). Population density of Reunion is approx. 351/Km2 (or approx. 218.1114/mile2)