This is the biography of Shakuntala Devi, the human computer, Guinness World Record Holder and a mathematical genius. She has also written many books, check out this one – and a murder mystery –

During a program at the Southern Methodist University in 1977, Devi correctly answered in 50 seconds to a question about the 23rd root of a given number with 201 digits. A special computer with large computation abilities took longer to calculate the answer.
The event that got her the place in the 1982 Guinness Book of Records took place at the Imperial College London in June 1980.

The computer department of the college had randomly picked two 13-digit numbers and Devi was asked to multiply them. She gave the correct answer in 28 seconds! The question was – 7,686,369,774,870 × 2,465,099,745,77, with the answer being 18,947,668,177,995,426,462,773,730

Shakuntala Devi’s husband was an IAS officer, named Paritosh Banerji She has a daughter called Anupama Banerji, whose bitter sweet relationship was explored in the biopic released by the same name in the year 2020.