Your system has a 64-bit kernel with 32-bit userspace, which is perfectly valid. Since Chrome is no longer updated for 32-bit systems, you need to enable support for 64-bit userspace; on Debian this is as easy as

sudo dpkg --add-architecture amd64
sudo apt-get update

Then you should be able to install the Chrome package, presumably with errors since you won't have the libraries installed; but

sudo apt-get -f install

should fix that; unfortunately the dependency list in the google-chrome package isn't complete, so you'll probably need to install

sudo apt-get install libexif12:amd64 libpulse0:amd64

to get Chrome running properly.

Cross-grading an i386 userspace to amd64 is also possible, but it's far more complicated and risky.