org.apache.commons.math3.primes
Class Primes

java.lang.Object
  org.apache.commons.math3.primes.Primes

public class Primes
extends Object

Methods related to prime numbers in the range of int:

• primality test
• prime number generation
• factorization

Since:

3.2

Version:

$Id: Primes.java 1462702 2013-03-30 04:45:52Z psteitz $

isPrime

public static boolean isPrime(int n)

Primality test: tells if the argument is a (provable) prime or not.

It uses the Miller-Rabin probabilistic test in such a way that a result is guaranteed: it uses the firsts prime numbers as successive base (see Handbook of applied cryptography by Menezes, table 4.1).

Parameters:

n - number to test.

Returns:

true if n is prime. (All numbers < 2 return false).

nextPrime

public static int nextPrime(int n)

Return the smallest prime greater than or equal to n.

Parameters:

n - a positive number.

Returns:

the smallest prime greater than or equal to n.

Throws:

MathIllegalArgumentException - if n < 0.

primeFactors

public static List<Integer> primeFactors(int n)

Prime factors decomposition

Parameters:

n - number to factorize: must be ≥ 2

Returns:

list of prime factors of n

Throws:

MathIllegalArgumentException - if n < 2.