Přečti si FAQ.
Q: Who can see my phone number?
On Telegram, you can send messages in private chats and groups without making your phone number visible. By default, your number is only visible to people who you've added to your address book as contacts. You can further modify this in Settings > Privacy and Security > Phone Number.
Bohužel tě to identifikuje. Jiný messanger jako reddit.com, nebo riot.im se bez toho obejde.