如何使用BigInteger？

import java.math.BigInteger;

BigInteger bigInteger1 = new BigInteger("12345678901234567890");
BigInteger bigInteger2 = new BigInteger("98765432109876543210");

BigInteger sum = bigInteger1.add(bigInteger2);
BigInteger difference = bigInteger1.subtract(bigInteger2);
BigInteger product = bigInteger1.multiply(bigInteger2);
BigInteger quotient = bigInteger1.divide(bigInteger2);
BigInteger remainder = bigInteger1.remainder(bigInteger2);

int compareResult = bigInteger1.compareTo(bigInteger2);
if (compareResult > 0) {
    System.out.println("BigInteger1 is greater than BigInteger2");
} else if (compareResult < 0) {
    System.out.println("BigInteger1 is less than BigInteger2");
} else {
    System.out.println("BigInteger1 is equal to BigInteger2");
}

int bitLength = bigInteger1.bitLength();
boolean isProbablePrime = bigInteger1.isProbablePrime(10);

byte[] byteArray = bigInteger1.toByteArray();
int intValue = bigInteger1.intValue();
long longValue = bigInteger1.longValue();