Cash value of points

As of this morning, I have 2,161,783 IHG points. I travel for work very often, and I have been a Diamond member as long as the category has existed. I do not have an IHG card (Skymiles Platinum instead).

Here's the thing; when I vacation, I always use Airbnb. I have looked at the site to purchase merchandise, but nothing really trips my trigger, so to speak.

Is there a cash value for these points? If so, how does one convert the points?