Primorial
noun ·Rare ·Advanced level
Definitions
- 1 Any number belonging to the integer sequence whose nth element is the product of the first n primes.
"For example, up to 10⁹, every positive integer which is a multiple of a primorial and is less than the following primorial satisfies the given inequality. There has also been little discussion on which primorials qualify in the different situations when RH fails."
- 2 A 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 is #92;textstyle 6#92;#35;#61;2#92;times 3#92;times 5#61;30."
Synonyms
All synonymsExample
More examples"For example, up to 10⁹, every positive integer which is a multiple of a primorial and is less than the following primorial satisfies the given inequality. There has also been little discussion on which primorials qualify in the different situations when RH fails."
Etymology
Blend of prime + factorial. Coined by American engineer and mathematician Harvey Dubner.
Related phrases
More for "primorial"
Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.