Arunachal Pradesh is the largest among the North- Eastern Indian States with an area of 83,743 square Km (32,333 sq mi). It borders Myanmar in the east, Bhutan in the west and the Tibet Autonomous Region of China in the north and north-east. On the south, the state shares inter- state boundaries with Assam and hills of Nagaland in the south-east. The capital is Itanagar. Formerly known as the North East Frontier Agency (from the British colonial era), the area was a part of Assam until it was made the union territory of Arunachal Pradesh in 1972, and in 1987, it became an Indian state.

Most of Arunachal Pradesh's terrain consists of deep valleys flanked by highland plateaus and ridges that rise to the peaks of the Great Himalayas. The State shares a total of 1680 kms (1043.904 mi) of international boundary with neighboring countries; 1080 km (670 mi) with China, 160 km (99 mi) with Bhutan and 440 km (270 mi) with Myanmar. The state extends from the snow- covered Himalayas to the Brahmaputra plains in Assam. It falls between 26° 30' and 29° 30' North latitude and 91° 30' and 97° 30' East longitude. As per 2011 census of the country, the population of Arunachal Pradesh is 1,383,727 of which 713,912 are male and 669,815 are female. As per projection, population of Arunachal Pradesh in 2021 is 17.49 lakhs.

A major part of the state is claimed by both the People's Republic of China and Republic of China (Taiwan) as part of the region of South Tibet.

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