Alexis Lemaire (born 1980), is said by the Sunday Telegraph and The Times newspapers to be "the greatest human calculator in history" (8 April 2005). Lemaire holds the last official world record for extracting the 13th root of a 100-digit number (13.55 seconds) and the last official world record for extracting the 13th root of a 200-digit number (267.77 seconds). The latter is a calculation known as the most difficult in history.

The 13th root of a 100-digit number

On 10 May 2002, Alexis Lemaire broke the record of the calculating prodigy Willem Klein, which was 88.8 seconds, and the unofficial one of Gert Mittring, which was 39 seconds.

On 23 November 2004, Gert Mittring attempted to break Alexis Lemaire's record, but it was officially rejected by the Guinness Book of Records, Saxonia Records Club, and the 13th root group.

On 23 November 2004, Gert Mittring calculated the 13th root of the following 100-digit number: 7,066,437,381,674,286,102,234,008,830,240,157,375,704,233,170,702,632,731,269,721,516,000,395,709,065,419,973,141,914,549,389,684,111 (47,941,071) in 11.8 seconds.

On 17 December 2004, Alexis Lemaire broke his unofficial world record, reducing it to 3.625 seconds (the time includes reading, calculating, and displaying the answer). He correctly computed the 13th root of the following 100 digit number: 3,893,458,979,352,680,277,349,663,255,651,930,553,265,700,608,215,449,817,188,566,054,427,172,046,103,952,232,604,799,107,453,543,533 - the root of which is 45,792,573.

The 13th root of a 200-digit number

On 6 April 2005, Alexis calculated the 13th root of a 200-digit number in 513.55 seconds, then broke his own record on 3 June 2005, reducing it to 267.77 seconds.

All these records are verified on the official 13th root website.

1980 births | Living people | Calculating prodigies

Alexis Lemaire