A Prime number is only divisible by itself and 1
I assume you are asking how do you work out the factors of a prime number. A prime number by definition only has itself and 1 as factors.
31 is already a prime number.
There is no work. The only prime number ending in 5 is 5.
The only way to know if a number is prime or not is to try and divide it by every number and if non of them work then it is a prime number
Work out if they have any factors, other than the number 1 and themselves. If they do not they are prime.
You just have to work out it,take each number below it and check whether it is prime or not.
A prime number is a number which is only divisable by one and itself, for example 2,3,5,7,11,13 However it is essential to remember that 2 is the ONLY even prime number and 1 is not a prime number because it is only divisable by itself prime numbers are mostly odd numbers.
Work it out dumb455
456
17 is a prime number because it has only two factors which are itself and one.
There is no quick way to work out if a number is prime or not, the only way is to see if it can be divided by any numbers that aren't itself or one.
Okay, so a prime number is a number where its only factors are one and itself. (7 cannot be divided by 2,3,4,5, or 6; only by 1 and itself, therefore it is a PRIME number).