Mumbai is the capital city of the Indian state of Maharashtra and the de facto financial centre of India. According to the United Nations, as of 2018, Mumbai is the second-most populous city in India after Delhi and the eighth-most populous city in the world with a population of roughly 2 crore. As per the Indian government population census of 2011, Mumbai was the most populous city in India with an estimated city proper population of 1.25 crore (12.5 million) living under the Brihanmumbai Municipal Corporation. Mumbai is the centre of the Mumbai Metropolitan Region, the sixth most populous metropolitan area in the world with a population of over 2.3 crore. Mumbai lies on the Konkan coast on the west coast of India and has a deep natural harbour. In 2008, Mumbai was named an alpha world city. It has the highest number of millionaires and billionaires among all cities in India.