Yes it is. Yours is a two digit book end as the first two and last two digits are the same. Interesting that the middle four digits are a repeater. As per serial number oddities: Bookend serial numbers have a matching block of digits on either end of the serial number. examples: 01757501 (2-Digits) 01075010 (3-Digits) stats: Bookends (2-Digits) 999,999 x Available Bookends (3-Digits) 99,999 x Available
That's a very generous definition. Conventionally, bookends are supposed to have zeroes in the middle, so 64000064 would be a bookend, but not 64191964. This makes a huge difference to the rarity; by your definition 1 in every 100 serial numbers is a bookend, while by the conventional definition it's 1 in every 1,000,000 serial numbers!
