Indonesia is the world's fourth most populous country, with 261,890,000 people, spread over 13,000 islands. The capital, Jakarta, has an estimated population of 10,370,000 (2017). One of the world's mega-cities, the mayor signed on to the 2014 Paris Declaration, Fast-track Cities: Ending the AIDS Epidemic (Cities Achieving 90-90-90 Targets by 2020).