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check if 2 divides the Number

check if 3 divides the Number

check if 5 divides the Number

...

check if any prime numbers less than the square root of the Number divide the Number

If any do, the Number is composite; otherwise the Number is prime.

This is called the Sieve of Erasthenes.

An easy way to check if a Prime number divides the Number in base ten (if you don't have a calculator) is to add or subtract 1 or 3 times the prime number to the Number, so that the sum or difference is a multiple of ten (if the prime number isn't 2 or 5). Knock off the zero. If the prime number divides the new number, it also divides the Number; otherwise it doesn't.

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Q: Algorithm to find whether a number is prime or not?
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No specific method has been discovered so far,not even by the greatest mathematicians,to create a prime number or to find out all the prime numbers......but there's a way to find whether a number is prime or not,i.e,by dividing that number with the first prime nos. such as 2,3,5,7,11 and so on and seeing whether it is exactly divisible or not.If it is not,then it can be classified as a prime no.


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You seek for prime numbers that are approximately 200 digits big, then multiply them. I don't know details about the algorithms, but I understand that for cryptography, instead of using an algorithm that will be guaranteed to give a prime number, an algorithm is used, instead, that has a very, very high probability of giving a prime number. Probably this is done because it is faster.


Algorithm to find prime numbers below ten?

Take each number in turn, call it "n", and check whether it has any factors f, such that 1 < f < n. If it doesn't, it is a prime number.Take each number in turn, call it "n", and check whether it has any factors f, such that 1 < f < n. If it doesn't, it is a prime number.Take each number in turn, call it "n", and check whether it has any factors f, such that 1 < f < n. If it doesn't, it is a prime number.Take each number in turn, call it "n", and check whether it has any factors f, such that 1 < f < n. If it doesn't, it is a prime number.


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What is the algorithm of LCM of more than 3 numbers?

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How can find prime number by using if in vbscript?

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Write a java programme to check whether the number is twin prime or not?

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How do you find the prime factorization of 34?

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You need at least two numbers to find an LCM. It doesn't matter whether they are prime or composite.