735
Authy got hacked, and 33 million user phone numbers were stolen
(appleinsider.com)
This is a most excellent place for technology news and articles.
Buy a few (at least 2 for a backup) yubikeys.
Much more secure.
You can store the TOPT codes on them, but then you can also do all the higher security things too.
No one's breaking into your Google account if you secure it with those keys and remove the sms backup method unless they've physically stolen the yubikey