HowTo Find out if Installed Linux is 32 bits or 64 bits

To figure out  whether we have installed Linux is of 32 bits or 64 bits, you can run the following command in a Terminal:
uname -mThe possible outcomes and their meanings are:

    * i686       : Installed 32-bit version.
    * x86_64 : Installed 64-bit version.



or try 


[root@rhel55 basil]# file `which file`
/usr/bin/file: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for GNU/