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Thread: BigInteger.isPrime

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    Default BigInteger.isPrime

    Hey guys. So I am trying to just get a method that can tell me if a BigInteger is FOR SURE prime, and I have had little luck. The best method that I have found online says 25 is prime... anyone know a good way to do it?

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    Default Re: BigInteger.isPrime

    You see, the computation of primes always was pretty difficult problem. You have to do lot's of computations to discover whether a number is a prime or not. The most straightforward algorithm is to check whether a number can be divided by some number less than it. And it appears to be pretty efficient, but not in the context of prime number generator.

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    Default Re: BigInteger.isPrime

    For large numbers, you would have to look deeper and study things like the Sieves of Eratosthenes, Euler etc ... (Sieve of Eratosthenes - Wikipedia, the free encyclopedia)

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