Check OS BIT is 32 or 64 For Solaris and Linux

Is my Operating System 64-bit?

In Solaris, from the command line (you don’t have to be root in most cases) run this command:
/usr/bin/isainfo -kv

If your OS is 64-bit, you will see output like:
64-bit sparcv9 kernel modules

If your OS is 32-bit, you will get this output:
32-bit sparc kernel modules

For Linux users :

If you are running Linux, you can check your distribution with the uname command:

uname -m

The output will read x86_64 for 64-bit and i686 or similar for 32-bit.

How about this Oracle install? Is it 64-bit?

The question here is weather your Oracle binaries are 64-bit. While some of the binaries associated with Oracle may be 32-bit, the important ones will be 64 bit. To check those, follow these steps from the command line:

cd $ORACLE_HOME/bin
file oracl*

This will display the file type of your oracle binaries. If you are running 64-bit binaries, the output should look like this:

oracle: ELF 64-bit MSB executable SPARCV9 Version 1, dynamically linked, not stripped
oracleO: ELF 64-bit MSB executable SPARCV9 Version 1, dynamically linked, not stripped

If your binaries are 32-bit, the output will look like this:

oracle: ELF 32-bit MSB executable SPARC Version 1, dynamically linked, not stripped