If you can see the actual lens of the camera from your apartment, you are in its line of sight. You would need to investigate the boundaries of the region or regions within your apartment where you are able to still see the lens of the camera.
Any glass between your apartment will have reflective properties, so when viewing the camera from the inside of your apartment, the light level within the apartment must be lower than outside to enable you to view the camera without interference from reflections. Conversely, if you are in the line of sight of the camera, it will only be able to see into your apartment if the light level outside your apartment is lower than that in your apartment.
Without further information (distances; apartment layout, including location of windows and apertures; how the camera is mounted, including tilt and centre of field of sight; etc.) there is insufficient detail to establish the geometry of the situation to provide a mathematical solution.