The Nicobar islands include 22 islands of different sizes. The largest one is Great Nicobar. The total land area of the chain is 1841 km². The highest point on the Nicobars is Mount Thullier at 642 m. The population of the islands was 42,026 in 2001, roughly 65% of whom are indigenous peoples (the Nicobarese and Shompen peoples, listed among the Scheduled Tribes of India), and 35% migrants from India and Sri Lanka.