You can’t get the number. You will not be able to obtain the number by browsing the Internet and asking questions on this website. Given that Taylor Swift is such a huge star, it would not be sensible for her to give her mobile number to anybody out there. If everybody on the Internet who liked her music were able to contact her on the telephone then she would never be hanging up the phone.
Hence, Taylor Swift and her agents ensure that nobody knows her mobile number is not used for purposes other than her friends, family and colleagues getting in touch with her.
If you want to get in touch with Taylor Swift, however, *YOU'RE GOING TO NEED A GREAT REASON. You will usually have to be able to offer her some kind of deal ?" either something related to advertising, to music, to television or more. People who are able to offer her work or some kind of contact will be able to contact her through her agents. That’s what the agents are for, and if you are able to offer her some kind of work like this then you’re going to need to get in touch with the agents first to see what they say. You’ll need to find out who the agents are and then discuss the deal with them before you are given access to some kind of direct contact to Taylor Swift herself.
If you want to contact her and you’re not offering something like this, then you can send her fan mail. Just like you can with other major stars out there, you can send a letter to a specific address and it will be delivered to Taylor Swift with all the other fan mail that she receives.