I think it depends on the apartment. You could get lucky and it might not be a big enough problem, or you could be unlucky and you could end up in a place that is like an acoustic sieve (as if there aren't any walls). Or you could end up with neighbors who don't care, or neighbors who are care a lot.
That sub looks very powerful to me and I bet that in some apartments it'll be easy for your neighbors all around you to hear it (well, they'll actually feel it, but still). If you're ambitious, you could try to ask the neighbors in the surrounding apartments where ever they may be (above you, below you, next to you, etc.) to help you find your maximum level where it's not too much with the premise of "I just don't want to be too loud and have no idea".
Alternatively I guess, you could wait a while to get a feel for how easily you can hear your neighbors. You might be able to base your maximum subwoofer level just on that if you're careful. Although, this isn't easy and it can take time. For example, it took me a very long time to finally realize that I was easily loud enough for my parents to hear. So I started paying attention to how easily I could hear them and I tried to find a balance. Now they say they no longer hear me.
I guess you could also listen from out in the hall by walking up and down the hall. It won't be accurate, but it might help.
I don't know if there are any special ways you could mount it to help minimize the "bleed" into the other apartments, but I guess if you can find a special stand or maybe if you place it on a thick pile of towels or blankets or something, I don't know.