About how many dwarf cories could I put in a 20 gallon? Also, would it be okay to house them with three otos?

I'm selling my old ten gallon which currently has my otos in it. I really would like to get some dwarf or possibly panda cories. My plan is to buy a 20 gallon, move the otos into there and then to see if I can put any cories in there.

I caught the catfish craze...

Thanks for your time!

Cory cats are a shoaling fish, so 5 or 6 should be the minimum number kept. I have four right now in a 15g, and I was gonna add at least one more, but they had babies so I am waiting until I figure out what to do with the fry. The otos should be fine with cories.

Are you planning on adding any other types of fish to the tank besides the catfish?