Maybe I am misjudging, but I would say top 10 is very, very hard given those statistics, and your letters would have to give good reason for another student with a better GPA to be rejected in favor of you.
There are a few ways that someone with tons of mathematical talent but poor past record can stand out. One is by showing terrific potential in research at this point. Another is by partaking in something such as the UK's famous Cambridge Part III program and surviving with good performance.
Also, the schools in the "top 50" are still very competitive in terms of what GPA they prefer, but they may be much more forgiving of a student whose undergraduate education has been less colorful, and doesn't have outstanding letters.
Remember, as always in the admissions game, those who get into the top 10 are simply the ones with the best applications. At times, this means they are also the best mathematicians, but not always. A lot of very good mathematicians will end up at very good, but not the most hyper-competitive, schools. Those schools will want people who have shown themselves extremely capable (acing their classes, even if at a not so famous school) despite not having tons of additional trophies.
I think you should focus on the top 50, not top 10; everyone wants to go to a top 10 school, but it's uncertain how many of those who don't get into one would actually have benefited most at one of them. A top 50 school will still require quite a bit from you, because a high GRE score does not tend to override the other factors.
I would say a high GRE score is nearly necessary, rather than sufficient, for a student with a low GPA to be considered seriously.