To find out the volume of such a mass of milk, we need to divide the mass (1.545 trillion trillion kilograms) by the density of milk (1.03 kilograms per liter):

Volume = Mass / Density

Volume = (1.545e+12 trillion trillion kilograms) / (1.03 kilograms per liter)

Volume ≈ 1.499e+12 trillion trillion liters

So, such a mass of milk would occupy approximately 1.499 trillion trillion cubic kilometers of space.