SQL Server 32-bit or 64-bit version?

You can use two different commands to check your SQL Server is 32-bit or 64-bit.

@@VERSION
It returns system and build information for the current installation of SQL Server.

SELECT @@VERSION

Sample result:
Microsoft SQL Server 2012 - 11.0.5058.0 (X64)
May 14 2014 18:34:29
Copyright (c) Microsoft Corporation
Express Edition (64-bit) on Windows NT 6.1 (Build 7601: Service Pack 1)

In the first line of the result, X86 = 32-bit, and x64 = 64-bit. Same is true for operating system.

SERVERPROPERTY('Edition')
The SERVERPROPERTY system function returns property information about the server instance. The 'Edition' property is the product edition of the instance of SQL Server. 64-bit versions of the Database Engine append (64-bit) to the version.

SELECT SERVERPROPERTY('Edition')

Sample result:
Express Edition (64-bit)

Hope this helps.