If i delete viber messanger from my iphone does it deactivate my account?

I'm wondering if doing so would deactivate my account!

Nope it just deletes the app (obviously lol)

No it won't delete the account, when you register on any other devices with the same number your account will be the same and your profile info will also be saved.
To deactivate you have to go to account settings and then de-activate the account.