Who called from 20734287

I answered this weird 8 digit number (no plus sign at the start indicating a country code).  I'm in the US, and it's clearly not a US number either... probably spoofed.  Anyways, there was silence (no background noise/static), and then they hung up after I said hello a few times.

I received a call from this weird 8 digit number a few minutes ago. No voicemail.

Same exact number just called my family's home phone today (cell phone yesterday).  No sound again.

And they called my cell AGAIN today.  Again, I picked up, heard silence, said hello a few times, and was hung up on.

We have received 4 calls with this bizarre looking number over the past 2 days - no messages are left.  Hoping that a block will work given that the number is not complete.