Who called from 2098098278

Keeps calling and when I answer, there is nobody there.
This has happened about 5 times in the last 2 days.

dont know who this is, but they call at all times and when you answer it there is nothing.

Keep receiving calls from this phone number (209-809-8278).  No answer on the other line.  Have received about 4 calls today. Don't know who it is, but noticed a lot of complaints from people regarding the same thing when I went on line to try and identify the caller.

Keeps calling and when I answer, there is nobody there.
This has happened about 5 times in the last 2 days.

Very annoying, had four calls this morning.  Every hour or two hours, exactly on the hour!  How do I report this or block them?