got a call, id says Ipema.  no one talked

Unwanted calls.

Multiple calls from this number. I don't answer calls from unknown people/numbers. No message ever left. Calls have been at various times from early morning, daytime, evening. Hate being awakened, having to get up to see who is calling,  interrupted meals, etc. I cannot fathom what kind of mentality gets joy from this cruel activity.

I get many calls from 949-249-9415.  When I answer nothing is said so I immediately hang up
.  They come one after another at various times of the day.  I would like to block calls from this number. How can I do that?