Help friends find you by phone number
Help people who have your phone number find you on Google services and connect with you. For example, your friends will be able to start a Hangout with you by typing in your phone number, or people may be able to see your name and profile photo when you call them or they call you.
When this setting is checked, it makes it easier for people who have your phone number to find you on Google services. When this setting is unchecked, people may not be able to look up your name, photo and public Google profile (and other profile information you have shared with them) via that phone number. Remember that regardless of this setting, people with whom you have shared your number on your Google profile will still be able to find you via that phone number.
Go here to change this setting. Please note that it typically takes a day or so for this change to take effect.
Enabling this option will not cause your phone number to appear on your Google+ profile; to add, edit, remove, or share numbers on your Google+ profile, please go to your Google+ profile page.