Claim: Nigeria is the most populous country in Africa, with 20 million people.

The Federal Republic of Nigeria -LSB- naɪˈdʒɪəriə -RSB- , commonly referred to as Nigeria , is a federal republic in West Africa , bordering Benin in the west , Chad and Cameroon in the east , and Niger in the north . Its coast in the south lies on the Gulf of Guinea in the Atlantic Ocean . It comprises 36 states and the Federal Capital Territory , where the capital , Abuja is located . Nigeria is officially a democratic secular country .   Modern-day Nigeria has been the site of numerous kingdoms and tribal states over the millennia . The modern state originated from British colonial rule beginning in the 19th century , and the merging of the Southern Nigeria Protectorate and Northern Nigeria Protectorate in 1914 . The British set up administrative and legal structures whilst practising indirect rule through traditional chiefdoms . Nigeria became a formally independent federation in 1960 , and plunged into a civil war from 1967 to 1970 . It has since alternated between democratically elected civilian governments and military dictatorships , until it achieved a stable democracy in 1999 , with the 2011 presidential elections considered the first to be reasonably free and fair .   Nigeria is often referred to as the `` Giant of Africa '' , owing to its large population and economy . With approximately 184 million inhabitants , Nigeria is the most populous country in Africa and the seventh most populous country in the world . Nigeria has one of the largest populations of youth in the world . The country is viewed as a multinational state , as it is inhabited by over 500 ethnic groups , of which the three largest are the Hausa , Igbo and Yoruba ; these ethnic groups speak over 500 different languages , and are identified with wide variety of cultures . The official language is English . Nigeria is divided roughly in half between Christians , who live mostly in the southern part of the country , and Muslims in the northern part . A minority of the population practise religions indigenous to Nigeria , such as those native to the Igbo and Yoruba ethnicities .   , Nigeria is the world 's 20th largest economy , worth more than $ 500 billion and $ 1 trillion in terms of nominal GDP and purchasing power parity respectively . It overtook South Africa to become Africa 's largest economy in 2014 . The 2013 debt-to-GDP ratio was 11 percent . Nigeria is considered to be an emerging market by the World Bank ; it has been identified as a regional power on the African continent , a middle power in international affairs , and has also been identified as an emerging global power . Nigeria is a member of the MINT group of countries , which are widely seen as the globe 's next `` BRIC-like '' economies . It is also listed among the `` Next Eleven '' economies set to become among the biggest in the world . Nigeria is a founding member of the African Union and a member of many other international organizations , including the United Nations , the Commonwealth of Nations and OPEC .