A trillion is equal to 1012 in the short scale, or 1018 in the long scale.

Written out in decimal form trillion (in the short scale) is:

1000000000000

In long scale:

1000000000000000000

## Alternative names

This number is also called tetrillion in Russ Rowlett's Greek-based naming system.

Aarex Tiaokhiao gave the name tetillion, referring to the value of this number. He also calls 1012 dudoocol, 12-noogol, or goonaoldecault, and it's equal to a(10,100,0)x in Aarex's Array Notation.

Wikia user NumLynx gave the name quadrasand for this number's short scale value.

Nicolas Chuquet coined byllion for 1018 (not to be confused with 1016), according to the Triparty en la science des nombres, which was previously lost and not rediscovered until 1880. Later it became billion in long scale.

Username5243 gave the name niloogolnoniplex, referring to the short scale value of this number.

BlankEntity calls this number Joogol.

## Examples

• It is the first -illion to exceed 1010 in the short scale.
• It is equal to 1 million squared in the short scale and 1 million cubed in the long scale.
• The nearest star to the Earth (besides the sun), Alpha Centauri, is over 26 trillion miles away or 41.842 trillion kilometers away.
• The human body contains somewhere around 50 trillion cells.
• There are roughly 3,500,000,000,000 fish in the world.
• The SI prefix tera- multiplies by one trillion.
• If one sandcastle contains one million grains of sand then you could make one million sandcastles with 1 trillion grains of sand.
• 1 trillion flops or operations per second is called a teraflop.
• A 2016 estimate says there are 2,000,000,000,000 galaxies in the observable universe.
• An estimate says there were 3.04 × 1012 trees on Earth in 2015.
• Andromeda Galaxy, which is part of the same Local Group as our galaxy, contains about 1012 stars.
• The surface of the human body houses roughly 1012 bacteria.
• 1.9786782 × 1012 is a rough estimate of the total number of links on Wikipedia.
• 1013 (ten Trillion)– The approximate number of known non-trivial zeros of the Riemann zeta function as of 2004.
• As of 2021, the number of known digits of π is 50,000,000,000,000 (5×1013).
• Approximately 1014 (one hundred Trillion) synapses in the human brain.
• 281,474,976,710,656 (248) possible unique physical addresses on MAC-48.
• 953,467,954,114,363 is the largest known Motzkin prime.
• There are 2 trillion galaxies in the observable universe.
• There are 3 trillion trees in the world.
• Some villains (usually extremely powerful ones) have killed trillions of people.

### As a banknote denomination

Some currencies, such as the German Papiermark and the Hungarian pengő, had banknotes with this number in the denomination.

## Approximations

For short scale:

Notation Lower bound Upper bound
Scientific notation $$1\times10^{12}$$
Arrow notation $$10\uparrow12$$
Steinhaus-Moser Notation 11 12
Copy notation 9 1
Chained arrow notation $$10\rightarrow12$$
Taro's multivariable Ackermann function A(3,36) A(3,37)
Pound-Star Notation #*(4,2,3)*4 #*(1,2)*8
BEAF & Bird's array notation {10,12}
Hyper-E notation E12
Bashicu matrix system (0)(0)
Hyperfactorial array notation 14! 15!
Fast-growing hierarchy $$f_2(34)$$ $$f_2(35)$$
Hardy hierarchy $$H_{\omega^2}(34)$$ $$H_{\omega^2}(35)$$
Slow-growing hierarchy $$g_{\omega^{\omega+2}}(10)$$

For long scale:

Notation Lower bound Upper bound
Scientific notation $$1\times10^{18}$$
Arrow notation $$10\uparrow18$$
Steinhaus-Moser Notation 15 16
Copy notation 9 1
Chained arrow notation $$10\rightarrow18$$
Taro's multivariable Ackermann function A(3,56) A(3,57)
Pound-Star Notation #*(4,1,3)*6 #*(3,1)*13
BEAF & Bird's array notation {10,18}
Hyper-E notation E18
Bashicu matrix system (0)(0) (0)(0)
Hyperfactorial array notation 19! 20!
Fast-growing hierarchy $$f_2(54)$$ $$f_2(55)$$
Hardy hierarchy $$H_{\omega^2}(54)$$ $$H_{\omega^2}(55)$$
Slow-growing hierarchy $$g_{\omega^{\omega+8}}(10)$$