java中超大大数字的计算方法

package study;

import java.math.BigInteger;

public class BigNum {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		BigInteger a=BigInteger.valueOf(1783178719);
		BigInteger b=BigInteger.valueOf(1783178719);
		System.out.println(a);
		System.out.println(b.add(a));//和
		System.out.println(b.subtract(a));//差
		System.out.println(b.multiply(a));//乘
		System.out.println(b.divide(a));//除
	}

}