He can do trigonometry in his sleep and solve a century-old problem, but Grigory Perelman couldn't solve one simple problem: Should I take the money and run? 

The eccentric Russian mathematician, dubbed "Mathsputin" in the press, was awarded a $1 million prize on March 30 for solving one of the most challenging problems facing contemporary mathematicians. Perelman told an official that he'd have to think about it.

Flash forward three months. 

Perelman told the Interfax news agency that phoned the Clay Mathematics Institute in Cambridge, Massachusetts, a week ago to say he was turning down the prize. According to Interfax, Perelman said he believes his contribution in proving the Poincare conjecture was no greater than that of U.S. mathematician Richard Hamilton, who first suggested a program for the solution.

The Clay Mathematics Institute confirmed in a statement on its Web site that Perelman had informed it of his refusal to accept the prize.

"On June 8-9 CMI held a conference in Paris to celebrate the resolution of the Poincaré conjecture by Grigoriy Perelman," the statement reads. "Dr. Perelman has subsequently informed us that he has decided not to accept the one million dollar prize."

The Poincare conjecture deals with shapes that exist in four or more dimensions.

Perelman has been described as a reclusive genius with a history of refusing big prizes. In 2006, Perelman made headlines when he stayed away from the ceremony in Madrid where he was supposed to get a Fields Medal, often called the Nobel prize of mathematics. He remained at home in St. Petersburg instead.

As for the new prize, Perelman has won the award regardless of where the money goes. So what will happen to the cash? That's up to the CMI. 

"In the fall of 2010, CMI will make an announcement of how the prize money will be used to benefit mathematics," the institute wrote in a statement.