This number is the PRI trunk line for various 1-800 services. Sometimes rather than displaying the proper caller id it will display this number.

This number is not tied to any specific person or service. When you receive calls from this number it could be someone calling your 1-800 number, it could be spam, or it could be a wrong number, you have no way of knowing.

Voip services such as voip.ms will often show the wrong CID when call forwarding.