Well, for $1 and the coolness index I'd probably keep it; it will make a neat conversation piece. From coolnumbers.com: The number you entered was 68577777. This is a very cool number! It has a Universal Coolness Index of 98.1% 68577777 contains a 5-of-a-kind together. Only 0.037% of 8-digit numbers have this combination. 68577777's digits sum to 54. In 1.5% of 8-digit numbers, the digits sum to at least 54. 68577777 has 4 unique digits. In 9.3% of 8-digit numbers, there are 4 or fewer unique digits.
I never knew about this index. Thanks! Out of curiosity, I checked my $100 note with the serial #91509150.......94.9% UCI Chris
Well, that's what is called a "repeater", 9150 repeats itself. There are collectors for those type. I'll occasionally find and keep one, but for me $100 is a wee bit much.