In the personnel office Buzz gives his social security number as 100-20-0853. Based on the the three number prefix and the standard at the time the number would have been issued in New York State (where his character is from). The second 2 digits are the Group number. Based on issuing standards at the time a valid number with group number of 20 would not have issued for more than 50 years in the future. Group numbers had only odd number prefixes from 11 to 99. After 2011 social security numbers are randomly issued. The Social Security Administration eliminates numbers that have been publicly used, so the number 100-20-0853 will never be issued.