Can primordial black holes substitute dark matter?

In some scenarios of Big Bang, the fluctuations of density in early universe result in the formation of various sized primordial black holes (BH). The black holes of mass range 10¹⁰ -10²² kg are good candidates for a dark matter. How many of such black holes (say, per cubic light year) are needed to constitute dark matter? Are those black holes observable? How would they move? How much gravitational waves would they radiate? Would they evaporate, or would they grow consuming interstellar matter or galactic dust? How frequent are collisions of such black holes with stars or planets and with each other? Would they consume stars - and if so, then how quickly? In our presentation we will give quantitative answer to these questionsb, based on known physics and our calculations. We will show that due to low number density, extremely small “cross section” of interaction of such BHs with the visible matter and very low “visibility” of such BHs due to low intensity of Hawkins radiation they emit, they indeed are very suitable candidates for a dark matter.