How to determine whether a given Linux is 32 bit or 64 bit?

login as: root
root@ProdDB01’s password:
Last login: Mon Mar 24 13:26:49 2014 from 172.42.8.51
[root@ProdDB01 ~]# uname -m
x86_64
[root@ProdDB01 ~]# getconf LONG_BIT
64
[root@ProdDB01 ~]#