Most likely spoofed number. We've noticed an increase in spoofed numbers from this area recently . Most likely telemarketers or spammers. If we don't know the number we don't answer. Legitimate callers will leave messages or will have a caller ID to identify themselves. If they don't then they shouldn't expect to be answered especially when telephone fraud is so prevalent these days.

I keep getting a call and they leave no message.

This number called yesterday and again a few minutes ago. No message left.

This number called me and left no message as well. Never seen it before.