LUSERS

Usage: LUSERS [*] [<server>]
Displays information about the number of users currently logged on to your server and the network. If you don't specify a server name, it will provide information of the server you are logged into. If you use it with a * it will get the lusers information from the target server.
If you designate a target server with no asterisk, then it will return the number of users that your server shows at the current time.
Examples:
/lusers
/lusers * arena.webchat.org
/lusers arena.webchat.org