Peyton Manning's Brother: If We Were the Kardashians, I Would Be ...

It's time to play "Keeping Up with the Mannings" ... with Peyton and Eli's older brother, Cooper Manning!!

Cooper -- who's a pretty successful oil and gas trader (safer than the NFL) -- was at LAX when we asked him a pretty great question ... if the Mannings were the Kardashians, who's Kim, Khloe & Kourtney??

You gotta watch the clip ... Cooper's answer is definitely NOT what you'd expect!

We also asked Cooper about a couple other things:

-- Do you get a "Manning Discount" at Papa John's?
-- How do we get RICH from oil stocks?
-- How's Peyton gonna do on Sunday?