A simple quadrilateral is a polygon that has four distinct vertices, has no straight angles and does not self-intersect.

Let $Q(m,n)$ be the number of simple quadrilaterals whose vertices are lattice points with coordinates $(x,y)$ satisfying $0\le x\le m$ and $0\le y\le n$.

For example, $Q(2,2)=94$ as can be seen below:

It can also be verified that $Q(3,7)=39590$, $Q(12,3)=309000$ and $Q(123,45)=70542215894646$.

Find $Q(12345,6789)mod135707531$.