Is the answer 2,397,207,667,966,701?

French "mathlete" Alexis Lemaire showed off his rare mental agility on Thursday, claiming a new world record after working out in his head the 13th root of a random 200-digit number in just 72.4 seconds.

Lemaire, a 27-year-old doctoral student in artificial intelligence from Reims, near Paris, was presented with the randomly-picked number by a computer, which displayed the figure over 17 lines on the screen.

Lemaire, who says he doesn't consider himself a nerd or a geek, then took just over a minute to identify two quadrillion, 397 trillion, 207 billion, 667 million, 966 thousand, 701 as the 13th root.



In other words, the number multiplied by itself 13 times produces the 200 digit number originally generated by the computer.

"The first digit is very easy, the last digit is very easy, but the inside numbers are extremely difficult," the mental gymnast said.

Lemaire, who sports a beard and glasses under thickly-matted eyebrows and a furrowed brow, previously performed the feat in 77 seconds and has been working at the 13th root problem for years, repeatedly eroding his best time.