Adding number: (206) 257-8334 and the number is in Washington state.  An area code and exchange lookup provides the following:
Area Code: 206
Prefix: 257
Location: SEATTLE
Type of service: CLEC

206-257-8334
206 257 8334
2062578334

I can't verify this but suspect this person is telemarketing health insurance, as we have suddenly had an increase in unsolicited calls trying to sell insurance saying we signed up online somewhere, though we did not.  Direct violation of the National Do Not Call Registry, as this is unsolicited and we do not have an established business relationship (EBR) with them.

It's possible this is a collections agency as well, though they never leave a voice mail and an online search was useless.

I'd be curious to see what others have to say about this number as well!

I have been complaining to the Washington Attorney General's Office: http://www.atg.wa.gov/FileAComplaint.aspx

Can also complain to the following:
National Do Not Call Registry: https://www.donotcall.gov/complaint/complaintcheck.aspx
FTC/Consumer Sentinel: https://rn.ftc.gov/pls/dod/wsolcq$.startup?Z_ORG_CODE=PU01
Fraud.org: http://www.fraud.org/