- It cannot be deleted
- It cannot be locked out (although you will get an event in Event Log that it was locked, but actually it is not)
- It will be enabled if you log into Directory Services Restore Mode or Safe Mode
To summarize - I would recommend to disable the account, because you always will get a chance to unlock it in Safe Mode if such time comes.
Second best option is to have a SIEM system or other notification mechanism in place which alerts you if accounts are locked out, this will allow you to notice brute force attacks to Administrator account early.