What's the right questions to ask before purchasing an apartment from a landlord?

[Rickey Brunson]

Currently looking at two properties that are both apartments

One is a 4 bd 2 ba for 460K for 82 days on market

the other is a 10 bd 10 ba 650K for 19 days on market

These are both for sale by owners, so the question I am asking is when buying a property from a landlord such as an apartment building what are the right questions to ask to make sure I get a good deal and you're not getting screwed over?