River NILE passes through the maximum number of countries. It passes through 11 countries: Tanzania, Uganda, Rwanda, Burundi, the Democratic Republic of the Congo, Kenya, Ethiopia, Eritrea, South Sudan, Sudan and Egypt. It is considered as the longest river in the world, and is approximately 4,258 miles (6,853 kilometers) long, but its exact length is a matter of debate. While River Danube goes through 10 counties, making it second.