As explained in this article: What is an IP address, each IP address must have an associated domain name. When we talk about domain name, it is not necessarily the domain name of a website. Your IP address is necessarily associated with a domain name. But rest assured, Internet users can not access your computer by entering this domain name in the navigation bar of their internet browser. Fortunately 🙂
With this Reverse DNS Lookup tool, you can see the domain name associated with your IP address. Each domain name associated with your IP address has been provided to you by your ISP or your Virtual Private Network (VPN) provider.
Some IP addresses may not provide you with a domain name. Because there are websites hosted on shared servers. Which means that the host hosts several websites on the same server. For more information on an IP address, go to the home page of the site and enter the IP address you want. You will get his hostname.
Reverse DNS : ec2-3-228-21-186.compute-1.amazonaws.com