My classmates borrowed money online, and I filled in my phone number without knowing it. I won't know until I get a text message. Will it involve me?

First of all, you should make sure that your identity information has not been leaked except your mobile phone number. You can call directly to ask who the borrower of this online loan is. After elimination, this has nothing to do with you. Although you left your phone number, you are neither a borrower nor a guarantor, and you don't need to bear any responsibility. Secondly, you can clearly tell the other party not to call or send text messages on the phone, and clearly tell the other party that you are neither a borrower nor a guarantor. You don't know why the borrower left your phone number or where the borrower is now. And clearly inform the harasser to call the police and block the phone.