57 is a
semiprime, a
Blum integer, and a
Leyland number. The split
Lie algebra E has a 57-dimensional
Heisenberg algebra as its
nilradical, and the smallest possible
homogeneous space for
E8 is also 57-dimensional. Although fifty-seven is not prime, it is jokingly known as the
Grothendieck prime after a legend in which the mathematician
Alexander Grothendieck gave it as an example of a prime number, not realizing it was divisible by three and nineteen. The same error was made by another famous mathematician,
Hermann Weyl, in a published article. ==References==