For me, 24 MP is the minimum, and it's wonderful that we can carry a camera in the pocket which makes decent-sized prints.
At 4000 x 6000 pixels, if we want to make a print at 360 dpi, we can make an 11x17 image and retain critical quality - as long as we don't crop.
That's the bare minimum for me, since my prints are usually 11x14 or larger. The limit here is the 4000 pixels, the smaller number.
I normally shoot 4x5 and 5x7 film where the numbers are a bit higher: even with an affordable consumer-grade scanner, 4x5 images are 45 MP or higher, and 5x7 are over 80 MP.