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

submitted 1 year ago by favrion@lemmy.world to c/math@lemmy.world

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

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[–] Lowpast@lemmy.world 9 points 1 year ago

Semiprime

[–] palebluethought@lemmy.world 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.

[–] PrincipleOfCharity@0v0.social 2 points 1 year ago

Semiprime numbers.