2001:4450:40::
Find the PTR record that belongs to an IP address.
PTR record
- Hostname
- Not available
- Reverse DNS name
- 0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.4.0.0.0.5.4.4.1.0.0.2.ip6.arpa
No PTR record is published for this address.
That is not unusual. Reverse DNS is set by whoever operates the IP range, and it is nowhere mandatory.