Although Delhi is listed with a higher population, Mumbai's city proper is the most populous in India. Not only that, but Mumbai is the wealthiest city in India. Bollywood is located in Mumbai. read more
SEE ALSO: East Coast city tops list of most energy efficient US cities. As of 2016, the world had 31 megacities -- cities with 10 million inhabitants or more -- and they are growing, in both size and number. According to the U.N., the world is expected to add 10 new megacities by 2030. read more