Evan claims that if he multiplies 1,458,362,287 buy two that the answer will be an even number without doing the multiplication how do you know that evan is correct

With multiplication, there are a few handy rules to remember:

If you multiply an even and an even, the answer will be even! 
If you multiply an odd and an odd, the answer will be odd!
If you multiply an even and an odd, the answer will be even!

Knowing this, if we go back and look at the numbers Evan is trying to multiply, we can try to use these rules! 

The last number of that really big number is a 7, which is odd, and the number 2 is even, and because we know that an odd number times an even number is an even number, Evan will be right!

820,000 is the answr