This is the phone number showing on scam calls being received with a pre-recorded message saying the IRS has been trying to reach you, and if you do not contact them they will sue you. I have received three of these calls in the past 48 hours.

IRS scam-ignore it and do not call them back.
Please report them: https://www.treasury.gov/tigta/contact_report_scam.shtml

Have gotten 5 calls in last 4 days.  Reported them to the IRS.  When I called the number on the recording, the scammer/agent asked for my name and my born date.  I asked where he was calling from.  He replied Washington. I said Washington State.  He said, No, Washington, DC.  That's when I called him a liar and told him to take his BS elsewhere.  I have lived in WA state and knew the 509 area code to be eastern WA. I then reported them to IRS for fraud.  Hope this helps you.

Received several calls from 509-570-1881. called then and told them I don't believe you they say they are...

IRS SCAM.  Female voice mail saying IRS is filing a lawsuit and I need to call their number.  Reported to Treasury department at link provided here... thanks for the link.