The Amazon River is widely recognized as the second-longest river in the world, with approximately 6,400 kilometers (3,976 miles) in length. The Nile River is the longest at around 6,650 kilometers (4,130 miles). The Ganga (Ganges) is not among the top three longest rivers. However, some recent measurements suggest the Amazon might actually be longer than the Nile, making this a debated topic in geography.