Impeller in intex model 635 broken where can I buy replacement part?

A late answer but it might help future Intex impleller sufferers... they do not sell replacement parts and you won't find any impellers sold separately anywhere on the planet. I've had 1 Intex pool and 3 Intex filter pumps in 3 years. Last week the 3rd pump's impeller broke as well. I shan't buy their products again.

I've repaired my intex spa with a boat part. If anyone wants the info I'll pass it on. It only cost 24 nz dollars & maybe 1hr of my time.

Intex pump is a toy. Very difficult to find a part for their pumps. You can find parts for the pool, but internal components for their pumps - Good Luck?!!
Made in China and like the old adage states: ...
You get what you pay for.
When searching for a replacement, get a real pool pump & filter upgrade. Go with a 16" or bigger Hayward or Pentair system Kit for Above Ground Pools. You will need to be a little bit of a thinker to transition real fittings to the Chinese Proprietary Intex parts, but it can be done, I have done it many times for my customers. And they thank me a million times over, once they see the exceptional performance they now have over the cheap, low quality equipment they have used for years. I have had customers that did not think that they could go a different route. And when their pumps died, they just got another one from intex. Until I came along...
So many happy campers now!
so you know what to ask your local service providers or retail store, or if you are a DIY'er, take a look...
Pentair Sand Dollar 16 5 in Pool Sand Filter System with 3 4 HP pump

or...
Hayward S166T92S Pro Series 16 Inch 1 Horsepower Top Mount Sand Filter...

Do not upgrade with another Intex product!