At the shell count() or find() returns error (see below) when referencing collection that named with numeric value. But, as a test created alphanumeric collection name and no errors

db.3330.find();
2017-07-02T18:32:05.050-0500 E QUERY [thread1] SyntaxError: missing ; before statement @(shell):1:2

3330.count()
2017-07-02T18:30:49.350-0500 E QUERY [thread1] SyntaxError: identifier starts immediately after numeric literal @(she

> db.opp_3330.count();
1