If you are worried about your privacy then it is advised that you do not share your phone number on Facebook. This will not come in way of accessing Facebook on your smartphone, as you can do so by logging on to the Facebook mobile site or downloading the app. But if you have already shared your phone number on Facebook to be notified of new posts, messages via SMS, etc. then you can restrict the access to your number. To do so, go to ‘Privacy Settings’, and under ‘Who can look me up’ you will find the option ‘Who can look you up using the email address or phone number you provided?’. Here, change the setting from ‘Everyone’ to either ‘Friends of Friends’ or simply ‘Friends’. Confirm the dialogue box with ‘Close’.