Dhaka (/ˈdɑːkə/ DAH-kə or /ˈdækə/ DAK-ə; Bengali: ঢাকা, romanized: Ḍhākā, Bengali pronunciation: [ˈɖʱaka]), formerly known as Dacca,[14] is the capital and largest city of Bangladesh, as well as the world's largest Bengali-speaking city. It is the eighth largest and sixth most densely populated city in the world with a population of 8.9 million residents as of 2011, and a population of over 21.7 million residents in the Greater Dhaka Area.[15][16] According to a Demographia survey, Dhaka has the most densely populated built-up urban area in the world, and is popularly described as such in the news media.[17][18] Dhaka is one of the major cities of South Asia and a major global Muslim-majority city. As of 2021, Dhaka's nominal GDP is estimated to be US$253.30 billion and GDP (PPP) is estimated to be US$510.276 billion.[11] Dhaka ranks 39th in the world and 3rd in South Asia in terms of urban GDP. As part of the Bengal delta, the city is bounded by the Buriganga River, Turag River, Dhaleshwari River and Shitalakshya River.