<p>Given an integer <code>columnNumber</code>, return <em>its corresponding column title as it appears in an Excel sheet</em>.</p>

<p>For example:</p>

<pre>
A -&gt; 1
B -&gt; 2
C -&gt; 3
...
Z -&gt; 26
AA -&gt; 27
AB -&gt; 28 
...
</pre>

<p>&nbsp;</p>
<p><strong>Example 1:</strong></p>

<pre>
<strong>Input:</strong> columnNumber = 1
<strong>Output:</strong> &quot;A&quot;
</pre>

<p><strong>Example 2:</strong></p>

<pre>
<strong>Input:</strong> columnNumber = 28
<strong>Output:</strong> &quot;AB&quot;
</pre>

<p><strong>Example 3:</strong></p>

<pre>
<strong>Input:</strong> columnNumber = 701
<strong>Output:</strong> &quot;ZY&quot;
</pre>

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

<ul>
	<li><code>1 &lt;= columnNumber &lt;= 2<sup>31</sup> - 1</code></li>
</ul>