The IRS will never call or e-mail you. They only notify you by U.S. Mail. The number is a spoof, but hey, at least they got the area code right. Was it a foreign accent?
I just received a call at 6:42 a.m. from "unknown" so didn't answer, but the recorded message on the answering machine said they'd been trying to reach me & it was my final notice that the IRS was filing lawsuits against me. At the same time a 2nd phone was ringing (1 is for a small home-based business). The caller ID on the 2nd one said "U.S. Government" (rather gutsy!) & was from 710-201-7286. The answering machine recorded the same "robot" message with a slightly foreign accent, about the lawsuits. Both messages said to call 929-800-4559.