Shakuntala Devi “The Human Computer” once extracted the 23rd root of a 201-digit number in 50 seconds, beating a Univac super computer, which took 62 seconds!
Shakuntala Devi , popularly known as the “Human Computer”, was a mathematical prodigy.
In 1977 in USA she competed with a computer to see who gives the cube root of 188132517 faster,undoubtedly she won.
That same year, at the Southern Methodist University she was asked to give the 23rd root of a 201-digit number, she answered in 50 seconds.Her answer—546,372,891—was confirmed by calculations done at the U.S. Bureau of Standards by the Univac 1101 computer, for which a special program had to be written to perform such a large calculation. She was not only correct but also beat the Univac super computer by a staggering 12 secs.
On June 18, 1980, she demonstrated the multiplication of two 13-digit numbers 7,686,369,774,870 × 2,465,099,745,779 picked at random by the Computer Department of Imperial College, London. She correctly answered 18,947,668,177,995,426,462,773,730 in 28 seconds.This event is mentioned in the 1982 Guinness Book of Records.
Unfortunately she passed away recently in Bangalore on April 2013.
Source: NY times