A thousand million millions.
1,000 x 1,000,000 x 1,000,000 = 1,000,000,000,000,000
Which is a 1 followed by 15 zeros
Using scientific notation: 1 × 1015
We could also think of it as a thousand trillion or a million billion.
• there are about a quadrillion ants on Earth (maybe 10 times more or less, no one knows exactly)
The prefix "peta-" means a quadrillion. Example: a petameter is a quadrillion meters.
(In many non-English speaking countries it means a million million million million, which is a 1 followed by 24 zeros, or 1 × 1024)
Below is a cube made of a million smaller cubes. If each of the small cubes is worth a billion dollars, then the whole cube is worth a quadrillion dollars.