AS3 XOR vs PHP XOR

Here is an odd (I think odd) thing.

  PHP:开发者_JAVA百科 539013259 ^ 12345 = 538976288
  AS3: 549013259 ^ 12345 = 539001010

Any ideas why the values are different? The best I can tell from Xor from both languages, the result should be the same.

I am unable to duplicate this behavior. At the PHP interactive shell:

php > echo 539013259 ^ 12345;
539001010