Fastest human computation

Mrs Shakuntala Devi of India correctly multiplied two 13-digit numbers (7,686,369,774,870  2,465,099,745,779) which were randomly selected by the Computer Department of Imperial College, London, on 18 Jun 1980; the feat took 28 seconds and the answer was 18,947,668,177,995,426,462,773,730. Some experts on prodigies in calculation refuse to give credence to Mrs Devi on the grounds that her achievements are so vastly superior to the calculating feats of any other invigilated prodigy that the invigilation must have been defective.