EIN and SSN Background
BOL User James Richards, author of the book "Transnational Criminal Organizations, Cybercrime, and Money Laundering" (CRC Press 1998) has created a detailed explanation of naming conventions, (Arabic, Russian, Hispanic, etc.) and how EINs and SSNs work, including a table showing EIN allocations by IRS Service Center.
Scroll down to page 15 of this document for the EIN/SSN info.)