In 1977 At university of USA she was asked to give mentally the 23rd root of 9167486769200391580986609275853801624831066801443086224071265164279346570408670965932792057674808067900227830163549248523803357453169351119035965775473400756818688305 620821016129132845564895780158806771 which was a 201 digit number. She answered it correctly with in 50 seconds which was 12 seconds faster than the UNIVAC 1108 computer which took 62 seconds to answer.
Shakuntala Devi is a very reputed personality of India. She is known to be a human computer because of her great computational power and also she is a great Indian mathematician. She born on November 4,1939 in Banglore, India. She has come from a very unusual family background. Her father was working in circus. From the age of 3 only she started showing her calculation power while she was doing card tricks with her father. At the age of six she demonstrated her calculation and memorization abilities at the University of Mysore.
On June 18, 1980 she demonstrated the multiplication of two 13-digit numbers 7,686,369,774,870 x 2,465,099,745,779 picked at random by the Computer Department of Imperial College, London. She answered the question in 28 seconds.
She is the author of the books Puzzles to Puzzle You, More Puzzles to Puzzle You, Book of Numbers, Figuring: The Joy of Numbers, In the Wonderland of Numbers, Super Memory: It Can Be Yours, Mathability: Awaken the Math Genius in Your Child, Astrology for You.
Yes she is non other then Shakuntala Devi. Just have look on her biography.
She proved to be so good with numbers, that her father left the circus and took her on road shows that displayed her amazing ability at number crunching.
In an interview she indicated that although she became very popular during her childhood, her child time was not so happy. At very young age she has the responsibility of her entire family.
About her books
Her books are also very popular. Everybody read her books. I can remember two books Puzzles to Puzzle You and More Puzzles to Puzzle you which I have also read.