There are 1,000 millions in a billion. There are 1,000 thousands in a million, 1,000 billions in a trillion, and 1,000 trillions in a quadrillion, which is also equivalent to a million millions.
It is very difficult to comprehend the sheer volume that large numbers represent. For example, a person bringing home a $40,000 annual salary would earn $1 million in 25 years, $1 billion in 25 thousand years and $1 trillion in 25 million years. With a United States population of 305 million people, each person would have to contribute $3,280 to make a combined total of $1 trillion.