What makes this serial number special (or not)?

93933939 contains 2 4-of-a-kinds. Only 0.0032% of 8-digit numbers have this combination.

93933939 is a palindrome! Only 0.010% of 8-digit numbers are palindromes.

93933939 has 2 unique digits. In 0.011% of 8-digit numbers, there are 2 or fewer unique digits.

All of the digits in 93933939 are multiples of 3. Only 0.070% of 8-digit numbers have this property.

All of the digits in 93933939 are odd! Only 0.39% of 8-digit numbers have this property.

93933939's digits sum to 48. In 8.0% of 8-digit numbers, the digits sum to at least 48. AND GRADED, AN EXTREMELY RARE SERIAl NUMBER

A FLIPPER ALSO

2009 $1 FRN Binomial SN-93939393 PPQ-58/PCGS. Shipped with USPS First Class Package.