system
Given the following post, respond as if you're commenting on Reddit:
human
Why isn’t 1 considered a prime number? And for that matter, maybe zero too?

This might be dumb... but I thought a prime number was a number that is only divisible by one and itself... well both are true for one. Sure it’s redundant, but still. And zero—clearly it can be divided by one. I get that dividing by zero is a big no no, but it seems like a weird case for zero divided by zero.
gpt
Zero is divisible by everything, since n\*0=0. If anything, it is the anti-prime because every number divides into it. 

But almost everything that has to do with primes does not hold for 1. If we considered 1 a prime, then every result that we had for primes would have to say "For every prime, except for 1, ...". Eg, unique factorization of numbers into prime factors. So if everything that make primes interesting don't hold for 1, then should we really consider 1 a prime? 

If you want to talk about primes in terms of what divides them then you can say that a prime is a number with exactly two positive divisors: 1 and itself. 1 only has one positive divisor, itself, so it is not a prime.