I'm sure OP meant 6 houses with several units in it each, not 7-11 people per house. Otherwise the distinction between house and unit doesn't make sense.
This is a small time landlord. Large landlords have easily over 10000 units, and he is one half of a percent of that.
I hope he is able to live off the rental income. It's a big job to manage 55 units and keep everything in shape and administratively going, deal with turnover and so on.
nah, having 6 buildings(not houses, if were being precise with terminology here) with multiple units in each, is not a small time landlord. If you can live entirely off the rental income then you are a full time landlord and can at best claim that you aren't a large corporate landlord, but you don't get to invoke the idea that you are some sort of mom and pop situation renting out a spare unit, which is what people assume when you say "small time landlord"