Go to survey option and uncheck the Show question number option.

It is unchecked...or am I not at the right place?

Are you checking this in preview link or live/ anonymous link?
Are they coming in the survey questions also, or just in response summary?

I am checking it in the Edit Survey/draft view (the only place I know where to find Survey Options). The numbers are not showing in live survey, only in response summary and in the pdf version of the summary, once the survey is completed. Hope this makes sense. Thanks much for your help!

This is not the intended behavior, so I would request you to publish the survey and take another test run in the incognito mode of browser. If it still occurs then reach out to support.
Before that try pasting the below CSS in the custom css under look and feel tab:
.ExportTag{display:none!important;}