NBC said it was the highest grand prize in game-show history.
Kravis defeated fellow finalist Brandon Saunders in Thursday night's final round to take home first prize. He is a recent Columbia Law School graduate who is about to begin his career as an attorney.
"This is all really incredible," Kravis said after his win. "I want to pay off my student loans and then maybe take a trip to Europe."
Ryan Seacrest served as host and producer of the show, which premiered Sept. 9.
It featured "contestants playing head-to-head trivia bouts inside a massive outdoor hourglass-shaped structure in midtown Manhattan and competing non-stop for a million seconds -- 11 days, 13 hours, 46 minutes and 40 seconds," a synopsis said.