Sudan, officially the Republic of the Sudan, is a country in Northeast Africa. Bordered by Egypt to the north, Libya to the northwest, Chad to the west, the Central African Republic to the southwest, South Sudan to the south, Ethiopia to the southeast, Eritrea to the east, and the Red Sea to the northeast. Sudan has a population of 43 million and occupies 1,886,068 square kilometres, making it Africa's third-largest country and also the third-largest in the Arab world. It was the largest country in Africa and the Arab world by area before the 2011 South Sudan's secession.