What Social Security Number (SSN) should I use for a Sandbox test account?

A Social Security Number (SSN) is required to create a PayPal Payments Pro account in the Sandbox test environment. Use "111" for the first three digits, followed by the two other number sets (a two-digit number and a four-digit number). You can use any set of numbers for the rest of the SSN, excluding the number 111-11-1111.