math

828 readers

1 users here now

General community for all things mathematics on @lemmy.world

Submit link and text posts about anything at all related to mathematics.

Questions about mathematical topics are allowed, but NO HOMEWORK HELP. Communities for general math and homework help should be firmly delineated just as they were on reddit.

founded 2 years ago

MODERATORS

mrh

Is there a name for numbers whose factors only consist of prime numbers but are not prime in themselves? (self.math)

submitted 1 year ago by favrion to c/math

3 comments fedilink hide all child comments

For example, 22 has factors of 2 and 11, both prime numbers, yet 22 itself is not prime.

top 3 comments

sorted by: hot top controversial new old

[–] Lowpast 9 points 1 year ago

Semiprime

[–] palebluethought 3 points 1 year ago

This would be true if and only if the number has exactly 2 prime factors. Otherwise, if n = abc, then a*b (or any other choice of two) is also a factor, and is not prime.

[–] [email protected] 2 points 1 year ago

Semiprime numbers.