Package 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

  • Method Details

    • 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.