Yes, it is a six of a kind, and good for liars poker. More importantly, it's a binary note having only 2's and 5's. The odds of finding a binary note are 1 in 8749. Source: http://coolserialnumbers.com/howrarearefancyserialnumbers.pdf
Also called a "binary" note because of the only two digits. I sell ones like this on eBay quite regularly for $10-$30 depending on condition. There is a market for unique serials.
