How many zeros are in a trillion trillion?

Answer 1

The number 1 trillion trillion can represent two different numbers, because there are two scales in use.

The short scale is used in the US, while the long scale is still employed for some uses in the UK, and elsewhere.

In the UK the "old term" is rarely used now.

The number 6 trillion trillion (short scale) is 1 x 1024, or 1 septillion, with 24 zeros.

The long scale assigns number names by millions, not thousands, so 1 trillion trillion

is 1 million, million, million; million, million, million or 1 x 1036 with 36 zeros.

Answer 2

Depends if you mean short or long scale trillion...

The Short Scale - used in the US and increasingly all over the world uses Billion and Trillion to mean a thousand million and a million million respectively.

Billion = 1,000,000,000

Trillion = 1,000,000,000,000

The Long Scale - tends to be used in non-english speaking countries and (actually more logical!) uses

Thousand Million for 1,000,000,000 and

Billion for 1,000,000,000,000

Trillion for 1,000,000,000,000,000,000

You'll need to figure out of your 999 Trillion is Short or Long - basically if it's in a modern English language source I'd assume short. so it would be

999,000,000,000,000