Anything shorter than 500 words is not going to impress the spiders. Somewhere around 800 to 1100 is probably better though if you are trying to generate content that provides any kind of significant value to a person actually wanting to learn something on the topic. I realize that many people who are simply writing for clicks will tell you that is a waste of time and that your text should simply be a vehicle to make people want to click off of your article. So, if that's how you approach it, go for it.
Personally, my best hubs as far as traffic and earnings are almost all over 2,000 words, some closer to 4k. So, the real answer to your question is that there isn't really a "right" or "wrong" answer. Just make sure it's over 500 words and that it's genuine and well-written.
As for images, Google likes user friendly content, which means a variety of media types, including photos and videos etc. It all needs to be relevant to the topic, but, if you think about it, common sense dictates that the most informative articles (if you are an unthinking search algorithm spider trying to determine such things) are going to at least appear to be the ones that offer a variety of approaches to the topic.