title: Decimal to hex for int64 in c
body: <p>Why this code does not work ?</p>
  
  <pre><code>#include &lt;iostream&gt;
  #include &lt;cstdio&gt;
  int main() {
    printf("%X", 1327644190303473294);
  }
  </code></pre>
  
  <p>I am getting o/p <code>5f264e8e</code></p>
  
  <p>but expected o/p is <code>126cbd5b5f264e8e</code> as given by below php script</p>
  
  <pre><code>&lt;?php
    echo dechex(1327644190303473294);
  ?&gt;
  </code></pre>