Wanting to replace tires on this bike don’t know what size they are.

I was given this bike a while ago and recently started riding it a lot but the tires I believe are original so they are cracking on the sides. I have 50 psi in both tires and I use 26inch 1.75-2.125 tubes. A number I found on the bike is M029192. The info that should be on the tire is worn off.