Why does that matter? When other routers are using the same channel it can pollute the signal, reducing the range of your WiFi and it's effectiveness. Think of a crowded room, the more people who talk at the same time, the nosier the room gets, and the harder it is to hear the one person you are talking to. It's similar with WiFi.
Simply changing channels can sometimes yield big results, restoring speed and extending range.
WiFi Analyzer on my smartphone and let it do it's thing. This free tool will check the channel spectrum wherever you are and offer an easy to understand star rating system, showing you which channel choices are better than others for your location. You even get suggestions on what channels to change your router over to. The more green stars, the better the channel.
WiFi Analyzer offers more than just star ratings, although for improving your signal that is probably the easiest part of the app to use. In my case I found I was on the most used channel in the area. I logged in to my router and manually changed the channel to the least-used channel, and the improvement was immediate.
The app will not only show you what channels are better than others, but do a "lite" version of a site survey, showing you what other wireless networks are visible from where you are, what level of security encryption they are using, their SSID (Wireless Network Name), signal strength, etc.
At times it can me interesting just to see what some of your neighbours are calling their WiFi and who is or is not securing it. In my last house one of the neighbours didn't secure their WiFi, so on the rare occasions I had internet problems I just hopped on their network until my service was restored.
At this point I must offer the standard "Secure your WiFi" warning. Not everyone who tries to connect to your WiFi is nice. In the case of my neighbour I could have accessed or deleted most of their files. I'll post another story on why you should secure your WiFi later, but for the moment please just do it if you haven't already, it can save you a world of problems.
There are other free analyzers out there. It doesn't really matter which one you use as long as you can understand the information it is providing, and use it to make your WiFi experience better.
-The Home Geek