I am not sure why that information would be relevant to get people to a wiki. Regardless, you can also find it at Special:Version. Scroll to the "Installed software" section; under the "Product" column, find "internals"; it is the number after "city_id:".
There are a bunch of wikis with "2004-11-11 23:33:14" as their creation timestamp. So either something major happened on that date or they just didn't track creation dates prior to then. I couldn't easily find a wiki with a creation date before that one.
Well, there is no point in avoiding perfectly valid numbers. That would just decrease the software's capacity. If what you meant was that you thought they would be padded (ex. 0000000001 and 0000000002), that is just a formatting thing.