Others on the list are Nigeria's Mike Adenuga with $4.6 billion, American media mogul Oprah Winfrey with a net worth of $2.8 billion (2018) and South African gold magnate Patrice Motsepe, with $2.9 billion, Nigeria's Folorunsho Alakija with $2.5 billion and Mo Ibrahim, a British billionaire of Sudanese Nubian ancestry, who has been on the Forbes Billionaire list since 2008 and in 2012 had a net worth of $1.1 billion.