Why I'm asking this: I know someone who's looking for a CEO for a funded startup with an apparently great product. I considered it briefly than wrote myself off

Why I'm asking this: I know someone who's looking for a CEO for a funded startup with an apparently great product. I considered it briefly than wrote myself off, deciding I was more of a CTO type and a CEO type, assuming a CEO deals more with the business aspects of the startup. Now however I'm wondering what a startup CEO actually does. Still not going to apply for the position but thought it would be interesting to solicit information here as to what qualities are needed for a startup CEO.