If you don’t’ plan on eating the potatoes you cooked within a few days, it is best to freeze them. They will not brown since cooking them destroys the enzyme that oxidizes. Like anything else, it’s best to store them with as little air as possible when freezing them. Once frozen, cooked potatoes can remain frozen up to one year. They will have no noticeable change in their quality or nutritional value. It is best to defrost them overnight in the fridge versus microwave defrosting them. The microwave can change the structure and result in changing the texture.