<p>Given an integer array <code>nums</code>, return <em>the sum of divisors of the integers in that array that have exactly four divisors</em>. If there is no such integer in the array, return <code>0</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [21,4,7]
<strong>Output:</strong> 32
<strong>Explanation:</strong> 
21 has 4 divisors: 1, 3, 7, 21
4 has 3 divisors: 1, 2, 4
7 has 2 divisors: 1, 7
The answer is the sum of divisors of 21 only.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [21,21]
<strong>Output:</strong> 64
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,2,3,4,5]
<strong>Output:</strong> 0
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 10<sup>4</sup></code></li>
	<li><code>1 &lt;= nums[i] &lt;= 10<sup>5</sup></code></li>
</ul>

class Solution:
    def sumFourDivisors(self, nums: List[int]) -> int:
        isFourDivisor = {}  # num: False, or sum if it's True    
        res = 0
        for num in nums: 
            if num not in isFourDivisor:
                divisors = set([1, num]) 
                for p in range(2, int(sqrt(num)) + 1):
                    if num % p == 0: 
                        divisors.add(p)
                        divisors.add(num // p)
                        if len(divisors) > 4: 
                            break

                if len(divisors) == 4: 
                    isFourDivisor[num] = sum(list(divisors))
                else: 
                    isFourDivisor[num] = False
            x = isFourDivisor[num]
            if x != False: 
                res += x
        return res
18400