int32 to IPv4

function int32ToIp(int32){
  if (int32 === 0) return "0.0.0.0";
  
  var bits = int32.toString(2);
  
  var ip = parseInt(bits.substring(0, 8), 2) + ".";
  ip += parseInt(bits.substring(8, 16), 2) + ".";
  ip += parseInt(bits.substring(16, 24), 2) + ".";
  ip += parseInt(bits.substring(24, 32), 2);
  
  return ip;
}