I used google authenticator and sms verification too the phone that I am using doesn't have any apps just email and authenticator for me to prevent hacking.
That is a good idea. If affordable, use a dedicated phone for Google Authenticator and the email. The email address should be dedicated for investment accounts only.
I have a sim lock on my phone number so that it cannot be transferred to another devise unless I go to the store in person with valid IDs.
Dedicated email to register on exchanges right? But still the information can be leaked from exchange or sold by exchange itself since it happened in the past so use email in your primary mobile and the authenticator on separate mobile better consider using Authy which is better than Google Authenticator.