Niger is 37% larger than Nigeria.
Area: 1,267,000 km2 World Factbook
Population: 17,466,172 (July 2014) World Factbook
Niger, officially the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. It borders Nigeria and Benin to the south, Burkina Faso and Mali to the west, Algeria and Libya to the north and Chad to the east. Wikipedia
Area: 923,768 km2 World Factbook
Population: 177,155,754 (July 2014) World Factbook
Nigeria, officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. Wikipedia