Algeria officially the People's Democratic Republic of Algeria (Al Jumhuriyah al Jazairiyah ad Dimuqratiyah ash Shabiyah), also formally referred to as the Democratic and Popular Republic of Algeria,[10][11][12][13] is a country in the Maghreb. In terms of land area, it is the largest country in Africa, the Arab World and of the countries bordering the Mediterranean Sea. It is the 10th-largest country in the world.[14] Algeria is bordered in the northeast by Tunisia, in the east by Libya, in the west by Morocco, in the southwest by Western Sahara, Mauritania, and Mali, in the southeast by Niger, and in the north by the Mediterranean Sea. Its size is almost 2,400,000 square kilometres (926,645 sq mi). It has an estimated population of 35.7 million (2010).[15] The capital of Algeria is Algiers. Algeria is a member of the Arab League, the African Union, OPEC and the United Nations. It is also a founding member of the Arab Maghreb Union