Shakuntala Devi is an Indian calculating prodigy.
In 1977 In Dallas she competed with a computer to see who give the cube root of 188138517 faster, she won. At university of USA she was asked to give the 23rd root of 91674867692003915809866092758538016248310668014430862240712651642793465704086709659 3279205767480806790022783016354924852380335745316935111903596577547340075681688305 620821016129132845564805780158806771.She answered in 50 seconds. The answer is 546372891. It took a UNIVAC 1108 computer, full one minute (10 seconds more) to confirm that she was right after it was fed with 13000 instructions.
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. However, this time is more likely the time for dictating the answer (a 26-digit number) than the time for the mental calculation (the time of 28 seconds was quoted on her own website). Her correct answer was 18,947,668,177,995,426,462,773,730. This event is mentioned on page 26 of the 1995 Guinness Book of Records. Shakuntala Devi happens to be an outstanding astrologer and gives remedies based on date and time of birth and place.