[Zope] How do I get a catalog to index numbers correctly?

I've got around 1000 items in my ZODB that have been indexed by several fields - keyword, description, etc. I've got a search page that allows searches on these fields, but when search for items using numerical keywords, I get no results. Example: I've got "Object123" with these keywords: object object123 123 Object123 comes up when I search "object" or "object123" but not when I search for "123" by itself. I can see the numerical keywords in the dictionary too. Please help. Thanks, Rob