The document lists and provides details on the top 10 longest rivers in the world. It discusses the Nile River as the longest at 6,650 km, flowing through 11 countries in Africa. The second longest is debated as being the Amazon River at 6,575 km or the Nile, with the Amazon's source uncertain and draining parts of 9 South American countries. The third longest is China's Yangtze River at 6,300 km, with over a third of China's population living in its basin. The fourth longest system is the Mississippi River at 6,275 km, formed from the Mississippi, Missouri, and Jefferson rivers draining 31 US states and 2 Canadian provinces.