Prime number question

**Paul M** · 26-04-2005, 05:05

A question prompted by a Radio Quiz;

Is the number one a Prime Number or not ?

It seems to fit the only definition I know - i.e. it is only divisible by itself and one ......

NitroNutter · 26-04-2005, 05:48

I beleieve so, been a long time since I seen a list of primes as an exercise tho

26-04-2005, 07:41

Quote:

Originally Posted by Paul M

A question prompted by a Radio Quiz;

Is the number one a Prime Number or not ?

It seems to fit the only definition I know - i.e. it is only divisible by itself and one ......

First about the definition: http://www.mazes.com/primes/defined.html

It is not a prime number, but...

Quote:

The number 1 is a special case which is considered neither prime nor composite .... Although the number 1 used to be considered a prime...

see http://mathworld.wolfram.com/PrimeNumber.html

Also:

http://primes.utm.edu/notes/faq/one.html

nffc · 26-04-2005, 08:13

What he said.

Prime numbers have two factors, themselves and 1.

As the number 1 only has one factor (it can't count twice) then it's not a prime.