Sudan is 47% larger than Niger.
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: 1,861,484 km2 World Factbook
Population: 35,482,233 (July 2014) World Factbook
Sudan, officially the Republic of the Sudan, is an Arab republic in the Nile Valley of North Africa, bordered by Egypt to the north, the Red Sea, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the southwest, Chad to the west and Libya to the northwest. Wikipedia