That sounds like a gigantic overestimation, really. What kind of particles are you talking about? Presently the high end estimate for particles in the observable universe is 10^82. I realize you did not say observable. Still, I don't know how one gets from 10^82 to 1,000,000^1,000,000 for a universe with a diameter of 46 billion light years. Homegeneity would demand a much smaller number, unless you are talking about sub atomic particles--quarks, leptons, etc. I still think it would be a smaller number than a million to the millionth power.Let's assume the beginning of the universe gave rise to 1,000,000^1,000,000 particles, and that may be conservative;