Question

At a height of 301 km above the Earth's surface, an astronaut finds that the atmospheric pressure is about 1.33E-8 mmHg and the temperature is 578 K. How many molecules of gas are there per milliliter at this altitude? (Enter the number of molecules, with no units.)

I am able to find the moles and deduce molecules from that but my answer is wrong. I keep getting 2.22E11