Lookup of 5.9.21.39
IP address: 5.9.21.39
Address type: IPv4
Host or reverse DNS (rDNS): static.39.21.9.5.clients.your-server.de
Country: 
Germany
5.9.21.39 does NOT belong to a private IP address block.
5.9.21.39 does NOT belong to a reserved IP address block.