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, France, 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 previously
performed the feat in 77 seconds and has been working at the 13th root problem
for years, repeatedly eroding his best time.

“I use an artificial
intelligence system which I use on my own brain instead of on a computer,”
he explained, matter-of-factly. “Personally, I believe most people can do
it but I have also a high-speed mind. My brain works sometimes very, very
fast.”

Via the Times of India