answersLogoWhite

0

1 cannot be a composite number because it is not divisible by any number other than itself.


It is not a prime because of the fundamental theorem of arithmetic: the unique prime factorisation theorem. This states that any positive integer greater than 1 can be expressed as a product of a unique set of primes. If 1 were considered a prime then you could add any number of 1s to the set of factors and the product would not change. For example,12 = 2*2*3 or 1*2*2*3 or 1*1*1*1*2*2*3 : so that the factorisation is no longer unique.

User Avatar

Wiki User

8y ago

Still curious? Ask our experts.

Chat with our AI personalities

EzraEzra
Faith is not about having all the answers, but learning to ask the right questions.
Chat with Ezra
DevinDevin
I've poured enough drinks to know that people don't always want advice—they just want to talk.
Chat with Devin
BeauBeau
You're doing better than you think!
Chat with Beau

Add your answer:

Earn +20 pts
Q: Why is 1 not a prime or a composite?
Write your answer...
Submit
Still have questions?
magnify glass
imp