Organization comparison class wikitable style width 5 style width 50 style width 50 Population 360 029 936 387 948 000 Area 13 953 041 km 5 382 910 sq mi 17 731 457 km 6 846 154 sq mi Population Density 24 33 km 63 sq mi 21 9 km2 56 7 sq mi Headquarters Cairo proposed Secretariat Headquarters Quito and Parliament seat Cochabamba Largest City Cairo 6 758 581 17 856 000 Metro S o Paulo 11 037 593 19 889 559 Metro Organization Type regional organisation and Political union regional organisation and Political union Official languages Arabic language Portuguese Spanish Dutch and English Main Religions 91 Islam 5 8 Christianity 4 Others Majority Christianity GDP nominal 1 898 trillion 7 672 per capita 2 879 trillion 7 421 per capita