Indonesia (Indonesian: Indonesia), or officially the Republic of Indonesia (Indonesian: Republik Indonesia), is a country located in Southeast Asia and Oceania. Indonesia consists of 17,508 islands. With a population of around 250 million, it is the fourth most populous country in the world and also the most populous Muslim country. Indonesia is a republic with a popularly elected assembly and president. The capital city of the country is the city of Jakarta on the island of Java. Its border neighbors are Papua New Guinea, East Timor and Malaysia. Other neighboring countries are Singapore, Philippines, Australia, Andaman and Nicobar Islands. Indonesia is one of the founding members of ASEAN and G20 member countries.