Just checking the obvious (I assume you have this right):
1. Your phone is iPhone. And on iPhone your phone number is listed in "can reach at".
2. You have your own contact card in Contacts, filled with that phone number, and in Preference, in Users & Groups you have that card set in your profile?
3. And you have the phone number in the AppleID configuration? Check on
https://appleid.apple.com/
May be call Apple support? Seems interesting challenge.