IP Address storage in D7?

In the sys_ip_members_visits table, anybody know what these numbers are?   If this is supposed to be IP address storage, what strange format is it?

It is a 32bit Decimal representation of a IPV4 dotted quad address.

It can be converted to dotted quad using the php function long2ip

In code, it's easier to deal with ip addresses as a standard integer without the dots.