Late Shakuntala Devi, known for her ability to make complex mental calculations, extracted the 23rd root of a 201-digit number mentally in the year 1977. Shakuntala Devi 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 on June 18, 1980, in just 28 seconds.
