I know that earth's effect is pretty small. As I recall though, there's a tendency for large-mass solid objects (especially close in ones) to spin like the Dickens at some stage in their development until they transfer their momentum and become tidally locked, which is part of what has happened to the earth because of the moon. I only mentioned it because in certain conditions it might be sufficient to nudge the figures a bit. OTOH, if this thing is close enough in to have a 13 day "year", on an object as long-lived as a red dwarf, it's probably tidal-locked or nearly so.
The angular momentum(AM) of a planet is derived from the AM of the whole system at it’s formation. If it’s too great, the system won’t form, and the greater it is, the longer it takes to form. So there’s an upper limit to the spin of the whole system from the beginning. The planets usually end up round. That wouldn’t happen, if there was a significant centrifical force at the equator. It would be an oblate spheroid. That pic does look like the equitorial radius might be ~17% greater than the polar radius though. That’s if it’s a pic of the planet and it’s not been distorted by a pic edit. In that case, the gravitational force at the surface would be would be 1.8, instead of 2.2.