This is pretty genius. Admittedly, it took me a while to figure out the approach you took here. But once it clicked, I realized how nice this is.

Nice job!

I was definitely going to say "This iterates through 4 times!" but then read the comments.

Definitely a good point that the list would only need to be lenght 10 to be valid in the first place.

So definitely think this is both clever and best practices.

Learn something new every day.

I'm wondering if the for loop can be optimized a bit more. At least for readability.

Had a feeling there'd be an algorithm for this. Didn't spend enough time looking :(

Gonna fork and play around with this a bit. See if I can understand the rounding and significant digits stuff.

What ways do you think this could be optimized? I'm assuming that instead of a split it would require something like a regex to get a number and test it before moving on, but it seems like it could get quite complicated.

This is awesome!

This is so nice and clean.

The sqrt(n) idea is pretty cool. I was playing with that but didn't nail it down.

Only thing I would think that could improve upon this would be to return the divisors in order. I guess you can do a sort on the array, but if there were a way to keep order, that'd be better.

Maybe 2 arrays? One for low and high? Then concat at end?

I really like this. So clean.

Agreed! The +/- 13 is really cool!

I'm asking because I don't know (not to say you're wrong). Is using closure here really a better way? What benefit does this give? It seems like you'll still have an anonymous functon anyways (return function() {}).

I really like this. Super simple!