More than 1.3 billion people live in India, making it the world's second most populous nation (just a whisker behind China.) That means many Indian states alone are equal in population to some of the world's biggest countries. India's largest state, Uttar Pradesh, for example, is home to more people than Brazil. The population of Maharashtra, meanwhile, exceeds Japan's. Even tiny Assam, the 15th most populous state in India, is more populous than Saudi Arabia. Here's a map of India in which each state is labelled as a country with a similar population size.