The IP-number of your machine is : 

54.204.73.51

The DNS-name of your machine is :

 51.73.204.54.in-addr.arpa name = ec2-54-204-73-51.compute-1.amazonaws.com.

Authoritative answers can be found from:
73.204.54.in-addr.arpa nameserver = ns2-24-us-east-1.ec2-rdns.amazonaws.com.
73.204.54.in-addr.arpa nameserver = ns1-24-us-east-1.ec2-rdns.amazonaws.com.
73.204.54.in-addr.arpa nameserver = ns4-24-us-east-1.ec2-rdns.amazonaws.com.
73.204.54.in-addr.arpa nameserver = ns3-24-us-east-1.ec2-rdns.amazonaws.com.