ST546v5 and strange default address

The information in the webpages of my router - a Thomson Speedtouch 546v5 using firmware v6.1.4.7 - is currently showing a strange address as "default gateway". I refer to the default gateway address that can be found at:

Broadband connection>Internet, view more>Details>TCP/IP Settings

It shows: Default Gateway 213.120.195.25

Does anyone know who or what owns this IP address and can give an explanation as to why my router should be using it? It's certainly not in my LAN-to-router range, nor in the range used for my router's address on the Internet, nor is either of my ISP's DNS addresses, so it must be referring to something that's way out there, on the Internet somewhere.

I did a Ripe and Who Is search but all I've been able to find is something that suggests it belongs to BT. Could this address be something to do with 'client transfer' performed by BT Wholesale? I recently migrated ISP.

Normally, what address should be seen against "Default Gateway", in "TCP/IP Settings" in this router? What is this "default gateway", anyway? It's not a default gateway from my LAN to my router, as that's something else entirely.

if you do a tracert you should find that it is the first line after the router - at least that is what mine is

Any trace route?

Yes, I've now done a tracert and you're right, it's the first hop (2nd location) after my router. It seems to refer to my ISP but also there's an indication there that it's part of bt.net.

So, it looks like a perfectly legitimate and harmless location.

Using reverse DNS

http://remote.12dt.com/lookup.php

gives

213.120.195.25 resolves to
"skymarkethg1.ilford.broadband.bt.net"
Top Level Domain: "bt.net"