That is one of their numbers - I suppose they can call people from one or the other (or many?) & "verify" by referring you to another of their numbers. Wonder if it's a one-man operation --- ?
The foreign male caller said he was calling from the U.S. Treasury Department. I responded with a "really!?!" He said, "OK, I don't want to waste my time." and hung up. These guys are trained in making us panic. The US Treasury Dept. doesn't call us!