There are three methods for Airtel check numbers, which are

1. You can use the USSD Code
2. You can also check your airtel number Via Airtel Thanks App
3. the best way to dial customer care for check airtel mobile number.
for more click here: https://webslosh.com/how-to-check-your-airtel-number/
Some USSD code which can help you for

For Balance *123#
For Number Check *282#
To Check 4G Data Balance *121*2# and Reply with “1”
Airtel Customer Care Number 198
Airtel Complaint Number 121
To Check Airtel Unlimited Packs *121*1#
To Check Offers *121#
To Check Plan Validity *123#
To Check Data Charges *121*7*5#
To Check Postpaid Current Bill Plan SMS “”BP”” To 121
To Check Postpaid Pending Amount SMS “”OT”” To 121
To Check Airtel Postpaid Bill Payment SMS “”PMT”” To 121
To Check Postpaid Current Plan Usage SMS “”UNB” To 121