Who called from 6502759000

I usually get the calls when I'm not paying attention but one time it called me and I noticed it, when I answered it hung up right away, creepy

California Solar Research or something like that. They have multiple lines (650-275-9xxx). Once you answer, they'll go on and on about putting up a sign at your home or filling a survey so that you can save on blah blah blah. Blocked the caller.