Sumatra comprises eight provinces of Indonesia. It is a sparsely settled island, with principal centers at Medan and Palembang; also important are Jambi, Padang, and Bandar Laumpung. There are state universities in Jambi, Medan, Padang, Pakanbaru, and Palembang. The four largest ethnic groups are the Acehnese, Batak, Minangkabau, and coastal Malays. In the interior highlands are found the Gayo-Alas and the Rejang-Lebong groups. Islam is the predominant religion, though there are many Christians among the Batak and the Gayo-Alas. Chinese, Arabs, and Indians live on the coasts, and some 15 different languages are spoken on the island.