On HTML export, if you add captions to images (with #+CAPTION), it will render as "Figure 1: the actual text". There is no way to not include the "Figure" or write a different word for it, short of substituting a different function altogether.
ODT export can customize it with a variable. This should also be the case for HTML export. Emacs : GNU Emacs 30.1 (build 1, aarch64-apple-darwin21.6.0, NS appkit-2113.65 Version 12.7.6 (Build 21H1320)) of 2025-02-24 Package: Org mode version 9.7.11 (release_9.7.11 @ /Applications/Emacs.app/Contents/Resources/lisp/org/)
