SOLUTION: I have read from the list that 103 421 is a prime number Is there a simple way to find if a number is a prime number or a composite number? I am very weak in maths. Thank yo

Question 351150: I have read from the list that 103 421 is a prime number
Is there a simple way to find if a number is a prime number or a composite number?
I am very weak in maths.
Thank you for your attention.

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Is there a simple way to find if a number is a prime number or a composite number?
I am very weak in maths.
----------------------------
Let's say you want to determine if 149 is a prime number.
---
1st: Find the square root of 149:
sqrt(149) = 12.2...
---
2nd: See if 149 is evenly divisible by any prime less than 12.2
149/2 = 74.5 no
149/3 = 47.666 no
149/5 = 29.8 no
149/7 = 21.2.. no
149/11 = 13.54.. no
----
3rd: If none of these primes divides 149, 149 is a prime number.
----
Cheers,
Stan H.

RELATED QUESTIONS
If you add a prime number to itself,is the sum composite or prime?... (answered by solver91311)

Is 44 or 56 a prime... (answered by funmath)

Is 187 a prime... (answered by AdolphousC)

is 1 a prime number? (answered by Nate)

Is 57 a prime... (answered by scott8148)

Is 57 a prime... (answered by scott8148,edjones)

is 5680 a prime... (answered by AAfter Search)

is 252 a prime... (answered by benazir.sj@gmail.com)

is 43 a prime... (answered by htmentor,ewatrrr)