To recover your Aadhaar number here's what you need to do:
Go to the UIDAI website uidai.gov.in
Click on the 'Retrieve Lost UID/EID' link
This 'Retrieve Lost UID/EID' tool can be used to retrieve your Aadhaar number (UID) as well as Aadhaar enrolment ID (EID).
In the next page, make sure 'Aadhaar Number' is selected on the left side of the page for receiving your Aadhaar number on mobile.
Fill in the personal details as specified against the required fields. You need to give your name, the mobile number or email address registered with Aadhaar and the security code as displayed on the form. "Your registered Mobile Number / Email which you had provided at the time of enrolment is mandatory to retrieve your lost UID / EID," according to the UIDAI website.
After entering these details, click on 'Send One Time Password' at the bottom of the form to proceed.
Upon a successful entry, the UIDAI facility sends an OTP or one-time password to the registered mobile number or email address.
On the next page, make sure 'Aadhaar Number' is selected on the left side of the page for receiving your Aadhaar number on mobile.