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.html 857555 2013-04-06 23:30:25Z luc \$

Method Summary
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 List<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

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 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.