title: Cubic root of a 128-bit integer in python
body: <p>I have a problem getting a cubic root of an approximately 128-bit integer in Python2. The following assertion gives me an error:</p>
  
  <pre class="lang-py prettyprint-override"><code>assert 188098593525197704876445094491719024115 == ((188098593525197704876445094491719024115) ** 3) ** (1.0/3)
  </code></pre>
  
  <p>I tried <code>Decimal</code> class with a precision set to 600 but it still gives me a value off approximately for 6-12 digits. </p>
  
  <p>How can I get this working (preferably without custom libraries)?</p>