Spain Business Directory: ESP is the ISO 3 alphabet country code of Spain. Currency of Spain is €, which has a short code of EUR. Capital of Spain is Madrid. Spain has the population of 46397452 and approximate area is 505370.00 square kilometers (or approx. 314036.918 square miles). Population density of Spain is approx. 91/Km2 (or approx. 56.5474/mile2)