To see a World in a Grain of Sand
and a Heaven in a Wild Flower,
Hold Infinity in the palm of your hand
And eternity in an hour.
~ William Blake

There are more atoms in a grain of sand than there are grains of sand on Earth.
And, there are as many galaxies in the universe as there are grains of sand on Earth (2 trillion).
There are on average 300 billion stars in each galaxy
Which means the number of stars in the universe is 300 billion multiplied by 2 trillion, or 600,000,000,000,000,000,000,000,000 stars.