Niger is 3,492 times larger than Gilbert, Arizona.
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: 363 km2 calculated
Gilbert is a town in Maricopa County, Arizona, United States, located southeast of Phoenix, within the Phoenix metropolitan area. Once known as the "Hay Shipping Capital of the World", Gilbert is currently the most populous incorporated town in the United States. Wikipedia