Why isn't 57 a prime number?

Factors of 57:
1 , 3 , 19 , 57
(it has more than 2 factors, so it is a complex number.)

3 x 19 = 57

No 57 is not a prime number because it can be divided by 1, 3 and 57.
A prime number is a number that can be divided by 1 and the number itself. So that is why 57 is not a prime number. Just because 5 and 7 are prime numbers that doesn't make them a prime number together.

Because you can divide it by 1, 57 and...3

Add up the integers 5 + 7 = 12 and again 1 + 2 = 3 so it's divisible by three!

Divide by three and you get 19 which is another factor!

Hope that helps!

No,57/19=3, and 3X19=57.

because you can divide it by 19.
57 / 19 = 3

a prime number is only divisible by itself.

Prime numbers are only divisible by 1 and the number itself. 57 is divisible by 3 and 19 therefore it is not prime

Prime number definition is that a number can only divide itself and one like 2 can divide by 1 and 2,itself so it is a prime number. So, the number 57 has a factors of 1,3,19 and 57.then it is a prime number.

Add the digits :

5 + 7 = 12, which is divisible by 3.

That is a quick and dirty check that it is a multiple of 3, and as mentioned before, 19 x 3 = 57.

57 is not a prime number because

3x19 = 57

a prime doesnt hav factors