Prerequisite : BigInteger Basics
The probablePrime() method will return a Biginteger of bitLength bits which is prime. bitLength is provided as parameter to method probablePrime() and method will return a prime BigInteger of bitLength bits. The probability that a BigInteger returned by this method is composite and does not exceed 2^-100.
Syntax:
public static BigInteger probablePrime(int bitLength, Random rnd)
Parameters: This method accepts two parameters as shown in the above syntax and described below.
- bitLength - bitLength of the returned BigInteger.
- rnd - source of random bits used to select candidates to be tested for primality.
Return Value: This method returns a BigInteger of
bitLength bits that is probably prime.
Exception:
- ArithmeticException - if bitLength < 2.
Below program illustrate the probablePrime() method:
Output:
ProbablePrime whose bit length is 4 = 13
Reference:https://docs.oracle.com/javase/7/docs/api/java/math/BigInteger.html#probablePrime(int, %20java.util.Random) 
