And the cool thing is, you can just put http://3626153261 in your browser address bar and end up at slashdot.org (news.ycombinator.com is behind CloudFlare, which doesn't allow IP-based access for obvious reasons)

Technically, anything you can name can be represented by a single integer.

Yeah but technically in the protocol it's just one number, we show it as 4 numbers because it's easier for humans to manipulate