Daniel Tammet (born 31 January 1979 as Daniel Paul Corney) is an English writer, essayist and autistic savant. Tammet has been studied repeatedly by researchers in Britain and the United States, and has been the subject of several peer-reviewed scientific papers.
Mental calculators are people with a prodigious ability in some area of mental calculation, such as multiplying large numbers or factoring large numbers. Some rare mental calculators are autistic savants, with a narrow area of great skill and poor mental development in other directions, but many are people of normal mental development who have simply developed advanced calculating ability. A good many are also experienced scientists, linguists, writers, and so on.