You have an anomalous school story. Feel free to revise my recommendation if you are some kind of crazy child prodigy and you think it's going to help you to point that out.
It's at least equivalent to bragging about your SAT score.
Probably not. Most "college credit" earned in US high schools is unfocused coursework that gets you out of (some of) your general-ed requirements. Lots of universities won't even transfer the stuff, and if they do, it's not typically treated as real college credit.
Aside from that, thanks to the prevalence of AP courses it's much easier (and more common) for high school kids to get college credits today. It's definitely not as impressive as it used to be, and citing the number of credits earned as if it were some kind of score is silly, at best. It's the sort of thing you brag about when you have nothing real to brag about.
A number of my friends did this though, so I don't think it's quite as big of an accomplishment in the US than elsewhere. Though I'll be the first to admit that my group of friends tended to be the high achievers in high school/university.
-- A undergraduate in CS/Mathematics
One thing I hate about bragging about that sort of thing is that it's (unfortunately) more of a reflection on the quality of the high school you attended than it is on your character. The best students at the worst high schools in the US don't have the same access to AP courses as the average student at the best high schools.
With that having been said, what do suggest we can do to help out with districts with less resources? I've done a lot of outreach, but it often feels like a drop in the bucket....
But, we take students from some magnet schools here to intern and they're amazing (multivariate calc, AP physics, and a year of Java--before senior year. The student had worked on a team project and was commenting his code unprompted...). I invited a Canadian colleague to a group meeting where they presented what they were working on she was stunned...I think that in the US when students have opportunities, it's great--the difficulty is how to improve the average....
At the best high school in Illinois you'd have roughly 2% of the graduating class be within shooting distance of that number, just to give you an approximation.
It really tell you knowing abut how the employee is going to approach problems and how creative their solutions will be.