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Numbers that can be factored down into 2 and only 2 prime numbers, such as:

25 (5 * 5)
9 (3 * 3)
12752041 (3571 * 3571)

Is there a mathematical term for these numbers? I did a bit of Googling, but it's tough to search for what something is called.

Update: To clarify, I meant the square of a single prime number. So n * n where n is prime.

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semiprime aaaaa – user50336 Nov 28 '12 at 16:42
When I looked up semiprime, it says it's a product of two prime numbers, but those prime numbers are not necessarily distinct. So 15 (3 * 5) could be semiprime, correct? – Mike Christensen Nov 28 '12 at 16:53
Not that I'm aware of. Frankly, I doubt it, cos' you can just call them squares of prime numbers. – Dan Shved Nov 28 '12 at 16:57
Thanks! Though @cassandra0's answer was helpful too. I'm learning about cryptography, and semiprimes come up quite a bit. – Mike Christensen Nov 28 '12 at 17:00
up vote 1 down vote accepted

The phrase "prime power" is usually used to refer to numbers of the form $p^n$ with $p$ prime and $n \geq 1$. I imagine "prime squared" or "prime square" is the most reasonable name for what you're describing.

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