The functions linking price, demand and supply have not been given, and these are essential for finding the equilibrium price and quantity.
What we would expect is demand quantity Qd=A-Bp where A and B are fixed numbers (unknown because not given), and, similarly, supply quantity Qs=C+Dp. Sometimes these are written, solving for p:
p=(A-Qd)/B and p=(Qs-C)/D. But we have only been given one price. We therefore have to assume that p=20 when Qs=500000 and also when Qd=700000, so 20=(Qs-C)/D=(500000-C)/D. Let's also assume that C=0, then 500000/D=20 and D=25000. This gives us the function Qs=25000p.
At equilibrium, Qs=Qd, so 25000p=A-Bp, p(25000+B)=A, so pe (equilibrium price)=A/(25000+B).
The equilibrium quantity Qe=25000A/(25000+B) [using the function Qs=25000p].
We also have Qd=A-Bp, 700000=A-20B, so B=(A-700000)/20.
pe=A/(25000+B)=A/(25000+(A-700000)/20)=20A/(A-200000). Clearly A>200000.
Qe=25000pe=500000A/(A-200000).
For example, if A=300000, then pe=6000000/100000=$60, Qe=Qs=150000000000/100000=1500000.
If A=700000, pe=14000000/500000=$28, Qe=Qs=700000.