Search, Quick Search doesn't find characters within a word

I find that the Quick Search is not able to locate characters that are part of a larger string. For example, I have a task with this phone number, 800-461-2273, in the title, and in numerous comments. Yet, when I use Quick Search and the term "2273", the task is not retrieved.

I've tried the Query syntax from the documentation, http://www.atlassian.com/software/jira/docs/latest/querysyntax.html, and the task is still not found.

Here are the Quick Search terms that I've tried which do not retrieve the proper task.

2273 - this obviously fails, as Quick Search thinks I've asked for a JIRA task number.
"2273"
"-2273"
"*2273"
"?2273"

Am I doing something wrong, or is the search method limited in its ability to find a subset of characters within a string?