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 × 10^{15}

We could also think of it as a **thousand trillion** or a **million billion**.

Examples:

• 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 × 10 ^{24})*

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.