eli5-Why is the number 1 not considered a prime number even though there isn’t any number that divides it?
In: 2
It’s a convention. We need to consider two things:
-The “primeness” of a number is related to multiplication, prime numbers are like the building blocks of it.
-But the thing is, 1 is a special number under multiplication, because it’s its identity element (also called neutral element). This means that, if you multiply anything by one, you get the same thing.
Now, the combination of both things means that using “1” blocks to create something is futile.
It’s like building a house, and having special magical bricks that if you add to the wall you’re building, the wall doesn’t change. Why would you add those bricks?
Latest Answers