FILTER_VALIDATE_INT - newbie question

Hello all, I'm having this strange behavior, and I do not understanding why... When I use FILTER_VALIDATE_INT I'm unable to get, on my input box, values starting with 0(zero), or values that are greater (in length) then 10 digits. I was expecting to be able to input the all range of integers. I've tried this: if (!filter_var($telefone, FILTER_VALIDATE_INT)) { $erros['telefone'] = 'Invalid Teléfono - Only Numbers Allowed.'; } And this: if (!filter_var($telefone, FILTER_VALIDATE_INT, array("options" => array("min_range"=>-1, "max_range"=>9999999999999)))) { $erros['telefone'] = 'Invalid Teléfono - Only Numbers Allowed.'; } And this: if (filter_var($telefone, FILTER_VALIDATE_INT, array("options" => array("min_range"=>0, "max_range"=>99999999999999999))) == false ) { $erros['telefone'] = 'Invalid Teléfono - Only Numbers Allowed.'; } No success. :s What am I not getting? Thanks, Márcio Ps- Anyone knows where can we grab a good source information about FILTER_VALIDATE_INT specifically?