We know that a prime factor of a positive integer is such a prime number, it is greater than 1 and can divide the number. What is the sum of all the prime factors of 2001?
我们知道，一个正整数的质因数是这样的质数，它大于1并且能整除该数．那么2001的所有质因数之和是多少．
<gadget id="calculator">3 + 23 + 29</gadget>
<output>55</output>

<result>55</result>