You can have as many administrators as you wish.
You can assign/remove admin permissions to members of your organization at any time.
You should be an administrator in order to do that.
How to do it?
Go to the web dashboard
Go to Organization Settings
- Go to the members section and click the (+) icon to open the window with all the members
- Identify the user you want to add/remove admin permission and use the icon at the right in order to assign/remove the permission
You can also have Teams Managers or single-team admins.
Learn more about roles and permissions.