Port-au-Prince (Haitian: Pòtoprens) is an arrondissement in the Ouest department of Haiti. It had 2,109,516 inhabitants at the 2003 Census which was estimated to have risen to 2,759,991 in 2015 in an area of 735.78 sq km (284.09 sq mi). Postal codes in the Port-au-Prince Arrondissement start with the number 61.