1.NounAny number belonging to the integer sequence whose nth element is the product of the first n primes.
2.NounA unary operation, denoted by the postfix symbol # and defined on the nonnegative integers, which maps 0 to 1, 1 to 1, and each subsequent number to the product of all primes less than or equal to it; the value mapped to by said operation for a given input.
"The primorial of
6
{\displaystyle 6}
is
6
#
=
2
×
3
×
5
=
30
{\displaystyle \textstyle 6\#=2\times 3\times 5=30}
."