Strange number of mbufs

[Artem Kuchin]

Running 5.4-CURRENT. Web server. About 150 virtual servers.

%netstat -m

4294481198 mbufs in use
4294662679/25600 mbuf clusters in use (current/max)
0/694/6656 sfbufs in use (current/peak/max)
3463545 KBytes allocated to network
0 requests for sfbufs denied
0 requests for sfbufs delayed
1681997 requests for I/O initiated by sendfile
75325 calls to protocol drain routines

What does this mean? Do i really have  4294481198 mbufs in use?
How is this possible? 

kern.ipc.nmbclusters is set to 25600

Regards,
Artem