I got a call from this number, but I let it go to voicemail. The voicemail just said to call this number back & something about a case number. It didn't pick up any other info.
After googling the number, I came across this page, & it would appear that I am being called by the same scammers, considering that the calls here are within hours of one another & within hours of my call, so then I googled "phone call claiming IRS lawsuit" to find this link.
https://www.irs.gov/uac/Newsroom/IRS-Reiterat ... -Telephone-Scam
This link has some great info on it, like the fact that "The IRS will always send taxpayers a written notification of any tax due via the U.S. mail. The IRS never asks for credit card, debit card or prepaid card information over the telephone."
The site has listed several methods of reporting scam calls like these. I would suggest that anyone who has gotten a call like this use one of those methods to report this number.
I also blocked my number & called the number back. It rang forever, not even an automated system picked it up, which is not something that the IRS would allow to happen. They would at least have an automated message telling you that call volumes are higher than normal.