Nigeria is 43% larger than S. Sudan.
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
Area: 644,329 km2 World Factbook
Population: 11,562,695 (July 2014) World Factbook
South Sudan, officially the Republic of South Sudan, is a landlocked country in northeastern Africa that gained its independence from Sudan in 2011. Its current capital is Juba, which is also its largest city. Wikipedia