Question

Why isn't 1 a prime number? :)

Answer 1

because there is only one factor for 1 and a prime number requires 2

Answer 2

caz many theorem will fail

Answer 3

The fundamental theorem of arithmetic states that you can represent any number uniquely as a product of primes


If 1 were prime, then a number like 12 can be written as


12 = 2*2*3

12 = 1*2*2*3

12 = 1*1*2*2*3

...etc

so 12 is being represented as a product of primes but it's not unique.


So make the representation unique, we exclude 1 from being prime


Note: the order of the factors doesn't matter

Answer 4

Beacause its too COOL

Answer 5

because nothing can go into it besides itself

Answer 6

Every prime number has exactly two factors! For example, 2 is prime because it only has factors 1 and 2. 3 only has factors 1 and 3. 5 only has factors 1 and 5.
Now, most non-primes, it's easy to realize, "Oh, okay, it has more than 2 factors."
1 is the unique case where it has fewer than 2 factors. Just 1 =/

Answer 7

THank you (: