There are minor drawbacks for some users, but turning off your ringers and answering service works great. You can simply check for any missed calls on your display or pickup when you're available if it's a call you want to accept. This works very well for landlines with a caller ID, which you would need anyways if using a call blocker. This is likely a spoofed number and just some jerk looking to steal information and/or money.
I receive calls from this number all day long , Last call was at 11 pm and 4 out 5 times they hung up when I answered and when I did hear something it was automated call rambling about health insurance at no time could I get to a live person to request to be taken off their calling list.