Saudi Arabia (/ˌsɔːdi əˈreɪbiə/ (listen), /ˌsaʊ-/ (listen); Arabic: السعودية as-Saʿūdīyah), officially the Kingdom of Saudi Arabia (KSA; Arabic: المملكة العربية السعودية al-Mamlakah ʿArabīyah as-Saʿūdīyah, pronunciation (help·info)), is a country in Western Asia constituting the bulk of the Arabian Peninsula. With a land area of approximately 2,150,000 km2 (830,000 sq mi), Saudi Arabia is geographically the largest sovereign state in the Middle East, the second-largest in the Arab world (after Algeria), the fifth-largest in Asia, and the 12th-largest in the world. Saudi Arabia is bordered by Jordan and Iraq to the north, Kuwait to the northeast, Qatar, Bahrain, and the United Arab Emirates to the east, Oman to the southeast and Yemen to the south; it is separated from Israel and Egypt by the Gulf of Aqaba. It is the only nation with both a Red Sea coast and a Persian Gulf coast, and most of its terrain consists of arid desert, lowland and mountains. As of October 2018, the Saudi economy was the largest in the Middle East and the 18th largest in the world. Saudi Arabia also enjoys one of the world's youngest populations; 50% of its 33.4 million people are under 25 years old.