Consecutive Numbers Sum
<p>Given an integer <code>n</code>, return <em>the number of ways you can write </em><code>n</code><em> as the sum of consecutive positive integers.</em></p>

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

<pre>
<strong>Input:</strong> n = 5
<strong>Output:</strong> 2
<strong>Explanation:</strong> 5 = 2 + 3
</pre>

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

<pre>
<strong>Input:</strong> n = 9
<strong>Output:</strong> 3
<strong>Explanation:</strong> 9 = 4 + 5 = 2 + 3 + 4
</pre>

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

<pre>
<strong>Input:</strong> n = 15
<strong>Output:</strong> 4
<strong>Explanation:</strong> 15 = 8 + 7 = 4 + 5 + 6 = 1 + 2 + 3 + 4 + 5
</pre>

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

<ul>
	<li><code>1 &lt;= n &lt;= 10<sup>9</sup></code></li>
</ul>
Math; Enumeration
class Solution:
    def consecutiveNumbersSum(self, n: int) -> int:
        n <<= 1
        ans, k = 0, 1
        while k * (k + 1) <= n:
            if n % k == 0 and (n // k - k + 1) % 2 == 0:
                ans += 1
            k += 1
        return ans
