However, if the value isn't to be used in any mathematical computation, i.e. it is some sort of ID number (or credit card number, etc), you may want to change it to Text. Especially if it is possible that it might have leading zeroes that you would like to retain.
One of my big pet peeves is that in importing Excel data into Access, it does not let you denote the field formats of the incoming data. Access tries to "guess" what it is, and sometimes guesses wrong. If it looks like a number, it will import it as a number. To get around this, you can export your Excel data as some sort of text file (CSV, tab-delimited, fixed width, etc), and then import that text file into Access. When you do that, you will be able to denote the format of the fields that you are importing (and can choose Text, if that is appropriate).