Forcing int to String

Hello, Hi, I am running a webservice using, nusoap. I am passing a 10 Digit Telephone number, and am getting back, '2146483647'. I know that this is the highest value of an Integer on a 32 bit platform, and thats is where '2146483647' is coming from. What I want to know, is how do I force the Number passed to nusoap to a string, instead of an Integer.. I have tried TypeCasting, strval($number). It still always returns '2146482647'. I don't know if this has been talked about, I searched and Nothing came up, can someone give me a hand.? Thanks Jared