Your phone itself often stores your number, which it reads from the SIM card.
On Android: Go to Settings > About phone (or About device) > SIM status or Phone identity. Look for "My phone number" or a similar entry under the details for your SIM card (e.g., "SIM slot 1 number").
On iOS (iPhone): Go to Settings > Phone > My Number. Your number should be displayed there.
Calling Another Phone:
The simplest method if you have access to another phone (a friend's, family member's, or even a landline). Just make a quick call or send a text message to that phone, and your number will show up on its screen (Caller ID).
If the above methods don't work, you can sri lanka phone number list call Vi customer care:
Dial 199 from your Vi number (toll-free).
Dial 198 from your Vi number (toll-free, primarily for complaints/requests). A customer service representative can tell you your number after verifying your identity.How to Know Your Vi Mobile No.