I do not know the reasons that you want to look up this cell number but that is also not important. What is important is that you find the information that you require. There are a couple ways you can go about it using both free and paid methods. att com directory
The extent of the free methods when doing cell phone number searches is using the major search engines like Google and Yahoo and Bing. What you would do is enter the cell phone number into the search bar and press search and see what comes up. Chances are you will get a bunch of irrelevant results so what you will have to do after that is try putting the phone number in quotation marks. That tells the search engine to look for that number only in that order and sometimes you can find some information that way. But you will probably not be able to find any identifying information using that method. att com directory

To find the identity of the phone number owner you have to use an AT&T reverse phone search directory. I know it sounds complicated but is actually really easy. The reputable directories allow you to do a free search just tried it out and to see if they have results for that phone number in their database. It takes you all of att com directory to do. The reputable directories also give you a 60 day, 100% no-hassle no questions asked money back guarantee which means that you are doing research with basically no risk. And considering the price for a one-time search is only $15 there is really no risk at all.