By MALCOLM RITTER and IRINA TITOVA, Associated Press Writers

ST. PETERSBURG, Russia – Who doesn't want to be a millionaire? Maybe a 43-year-old unemployed bachelor who lives with his elderly mother in Russia — and who won $1 million for solving a problem that has stumped mathematicians for a century.

Grigory Perelman can't decide if he wants the money.

"He said he would need to think about it," said James Carlson, who telephoned Perelman with the news he had won the Millennium Prize awarded by the Clay Mathematics Institute of Cambridge, Mass.

Carlson said he wasn't too surprised by the apparent lack of interest from Perelman, a reclusive genius who has 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 (PER-il-mahn) told a local television station he hasn't made a decision on whether to accept the money, and that Carlson's institute will be the first to know when he does.

Sergei Rukshin, Perelman's high school math teacher, told The Associated Press on Monday that Perelman is still unsure whether to accept it.

'Nyet' to $1 million? Math genius may reject award - Yahoo! News