45. Andrew Beal
Beal dropped out of college twice. He was apparently too busy building his first fortune in real estate, flipping apartment buildings. Later on, the Texas banker made a tidy sum during the Great Recession purchasing distressed assets. A mathematics enthusiast, Beal developed a hypothesis relating to a 300-year-old math problem, later dubbed the Beal Conjecture. He has since offered $1 million to anyone who could prove or disprove it. Nearly 25 years later, nobody has.