Karachi is the commercial capital of Pakistan. It is the largest and most populous city of Pakistan. It has a population of around 25 million. It extends over an area of about 3527 sq. Km and it is a metropolitan city. read more
EDIT: The population of Karachi is slightly larger than that of Mumbai, with 23.5 million in Karachi and around 22.5 million for Mumbai as of 2015. Also the name of Karachi is longer than that of Mumbai and comes before Mumbai if arranged alphabetically. read more