Elon Musk vs. Larry Ellison

Musk, who says he's worried about population collapse, has nine children with three women, including triplets and two sets of twins. As a kid in South Africa, Musk taught himself to code; he sold his first game, Blastar, for about $500.

Ellison never finished college. He started out building databases for the CIA. Daughter Megan has financed films such as Zero Dark Thirty and American Hustle; son David produced mainstream movies like The Terminator and Mission: Impossible".