On Google Plus anyone can invite you over a video Hangout or anyone can comment on your posts unless the privacy section is dealt particularly. Google Hangout application for iPhone and Android devices have the provision to control the privacy with which they followers or friends can interact with you Hangout either on the desktop or the applications for both the platforms. The screenshot and the tip has been mentioned for the Android devices, but the exact same steps can be used to do the same for the iPhone application as well.
Open the application and then go to its Settings section. Now tap the Customize invites option.
Privacy has been differentiated as per the circles affiliated to your Google Plus profile. Let’s say, Friends will directly invite you to the hangout session and you will just have to click the link to start the hangout, whereas in the case of other circles like entertainment the people will be able to send you an invitation for the Google Hangout on the acceptance of which the Hangout will start.
Here hangout refers to both way to interaction, i.e. video and audio both. You can change the level of this invitation to the hangout for all the circles related to your profile.
If you are still facing lots of invitation on your profile then you can opt to snooze the notifications for the next 72 hours or you can go to the settings section and then uncheck the checkbox for the notifications for Hangout Invitations. This will save your phone from buzzing every time any tries to invite you to the Hangout.