Denny Cherry shows us how to find the number of NUMA nodes a SQL Server has:
The next way to see what your NUMA configuration is, is to look at the ERRORLOG file. Every time SQL Server is started it will log the NUMA configuration towards the beginning of the ERRORLOG file. That line will look something like this example.
Server Node configuration: node 0: CPU mask: 0x00000000000000ff:0 Active CPU mask: 0x00000000000000ff:0. This message provides a description of the NUMA configuration for this computer. This is an informational message only. No user action is required.
Denny shows four different ways of getting this answer, and then provides some general advice on the maximum number of nodes you probably want.