How many commercial real estate brokers/agents are there in the US?

Within the major firms (CBRE, Grubb, NAI, Colliers, etc), there are
approximately 35,000 commercial brokers.  Add in the commercial
brokers that are affilated with what are otherwise seen as residential
brokerages (Century 21, Remax, etc) and the figure grows by another
25,000.  The hardest to track, however, are the small shops that
specialize in local commercial brokerage.

Firms that deal in marketing to commercial brokers usually say there
are between 90,000 and 125,000 full time commercial brokers in the US.

Hope this helps.