The latest stable kernel version is 2.6.27. Indeed you're running a bit older version 2.6.16. Regarding the other numbers in your kernel version, take in mind the the first four are the actual version (kernel version 2, major release 6, minor release 16, bux fix and security patches 54). The other numbers are introduced by the developer of your Linux OS (SuSE) and I guess they serve for internal reference.
For example on my OpenSuSE 10.3 I have:
$ uname -r
from which I simply state that my running kernel is 2.6.22 or even 188.8.131.52.