org.apache.commons.math3.primes

Class Primes

java.lang.Object

org.apache.commons.math3.primes.Primes

public class Primes
extends java.lang.Object

Methods related to prime numbers in the range of int:

• primality test
• prime number generation
• factorization

Since:

3.2

Constructor Summary

Constructors

Modifier	Constructor and Description
private	Primes() Hide utility class.

Method Summary

Methods

Modifier and Type	Method and Description
static boolean	isPrime(int n) Primality test: tells if the argument is a (provable) prime or not.
static int	nextPrime(int n) Return the smallest prime greater than or equal to n.
static java.util.List<java.lang.Integer>	primeFactors(int n) Prime factors decomposition

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Primes

private Primes()

Hide utility class.

Method Detail

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 java.util.List<java.lang.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.