I think the previous answer was off topic from what this question was really asking. We believe that the universe is for the most part, a closed system. I say "for the most part" because there are...
The total mass of the Universe is: 100,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 tonnesE = MC^2
So your answer would be: the Universe has * 10 = 2.99792458 × 1061...
The stars are powered by nuclear fusion, so this is widespread. Nuclear fission is more unusual and probably only occurs in certain planets where there is a lot of uranium.