title: Negative 64bit Decimal Number to Binary in php
body: <p>I am trying to convert a decimal number for example </p>
  
  <blockquote>
    <p>-268427136</p>
  </blockquote>
  
  <p>to binary and vice versa.</p>
  
  <p>If I try with windows Calc, binary notation for this number is: </p>
  
  <blockquote>
    <p>1111111111111111111111111111111111110000000000000010000010000000</p>
  </blockquote>
  
  <p>If I try bindec,decbin or base_convert:
   <code>echo(decbin(-268427136));</code> Outputs: </p>
  
  <blockquote>
    <p>11110000000000000010000010000000</p>
  </blockquote>
  
  <p>Or <code>echo(bindec('1111111111111111111111111111111111110000000000000010000010000000');</code> Outputs: </p>
  
  <blockquote>
    <p>1.84467440734E+19</p>
  </blockquote>
  
  <p>What could I use in php to achieve same result? </p>