The result of multiplying all prime numbers up to and including a given prime number.

For example the primorial of 5 is P(5) = 2 x 3 x 5 = 30

Here are the first few primorials:

P(2) = 2

P(3) = 2 x 3 = 6

P(5) = 2 x 3 x 5 = 30

P(7) = 2 x 3 x 5 x 7 = 210

P(11) = 2 x 3 x 5 x 7 x 11 = 2310

P(13) = 2 x 3 x 5 x 7 x 11 x 13 = 30030

P(17) = 2 x 3 x 5 x 7 x 11 x 13 x 17 = 510510

etc

See: Prime Number