在Java中计算大于整数和long的阶乘？

您可以在Java中使用BigInteger，它可以根据需要使用任意数量的数字

    BigInteger fact= BigInteger.ONE;    int factorialNo = 10;    for (int i = 2; i <= factorialNo; i++){      fact = fact.multiply(new BigInteger(String.valueOf(i)));    }    System.out.println("The factorial of " + factorialNo +          " (or " + factorialNo + "!) is: " + fact);   final int digits = fact.toString().length();   BigInteger number = new BigInteger(fact.toString());   BigInteger reminder;   BigInteger sum = BigInteger.ZERO;   BigInteger ten = new BigInteger(String.valueOf(10));   while(number.compareTo(BigInteger.ONE)>=0)     {     reminder=number.mod(ten);     sum=sum.add(reminder);     number=number.divide(ten);     }     System.out.println("The total sum of all the " + digits          + " idividual digits from the answer of the factorial of "          + factorialNo + " is: " + sum

编辑 ：改进了代码，使其与作者的代码兼容