Yes, for people it might be a better to remember but for search engines it is like another keyword in it.

Number,hyphens, don't quite matter. All it matters is how you build your website, how you promote it and what it has to offer.

There are thousand of live examples out there where domain names don't have anything to do with something easy to remember/catchy.

It's always better to keep it simple. Unless your company name has a number in it, stick with the letters, it's what most people think of first when doing a broad search.

Right, including number like 2 or 4 in your domain names would be helpful for shortening your domain names and they would be no difficult for search engines but I think it would hard to spread by way of the mouth.

Thanks,

It is a nice way to get short domain name, a domain that can be easy to remember and it is also eye cash....