This number as well as a bunch of other 504 exchange phone numbers (Redondo Beach) call me constantly. I never pick up, most likely they're spoofed, & they never leave a message, standard operating procedure for spammers, scammers, & telemarketers. It's a big time-suck.
FTC Data
At least 1 consumer from Colorado reported phone number 310-504-5680 to the Federal Trade Commission. 100% of complaints reported the call or text message as a robocall or recorded message. The last complaint was on February 17, 2021.
Boulder
Help others by rating this number - was it spam, a business, or something else?
A number from Tiburon CA called, I didn't answer. Immediately, this number called. I picked up. A woman was seemingly in mid-"conversation" but it sounded like a fake conversation.