Understanding Large Numbers

Bigger than a trillion

Have you ever wondered what number comes after a trillion? Or how many zeros there are in a vigintillion? ​Someday you may need to know this for science or math class. Then again, you might just want to impress a friend or teacher. 

Numbers Bigger Than a Trillion

The digit zero plays a very important role as we count very large numbers. It helps us track these multiples of ten because the larger the number is, the more zeroes are needed.

NameNumber of ZerosGroups of (3) Zeros
Thousand31 (1,000)
Ten thousand4(10,000)
Hundred thousand5(100,000)
Million62 (1,000,000)
Billion93 (1,000,000,000)
Trillion124 (1,000,000,000,000)

Grouping Zeros by Threes

Many of us find it easy to understand that the number 10 has one zero, 100 has two zeros, and 1,000 has three zeros. We use these numbers all the time in our lives, whether it is when dealing with money or counting something as simple as our music playlist or the mileage on our cars.

When you get to a million, billion, and trillion, things become a little more complicated. How many zeroes come after the one in a trillion?

It's hard to keep track of that and count each individual zero, so we break down these long numbers into groups of three.

For example, it's much easier to remember that a trillion is written with four sets of three zeros than it is to count out 12 separate zeroes. While you might think that one's pretty simple, just wait until you have to count 27 zeros for an octillion or 303 zeros for a centillion.

It is then that you will be thankful that you only have to remember 9 and 101 sets of three zeros, respectively.

The Powers of Ten Shortcut

In mathematics and science, we can rely on the "powers of ten" to quickly express exactly how many zeros are needed for these larger numbers. For example, a shortcut for writing out a trillion is 1012 (10 to the power of 12). The number 12 tells us that we will need a total of 12 zeros.

You can see how much easier these are to read than if there were just a bunch of zeros.

  • Quintillion = 1018 or 1,000,000,000,000,000,000
  • Decillion = 1033 or 1,000,000,000,000,000,000,000,000,000,000,000

Googol and Googolplex: The Enormous Numbers

You are probably very familiar with the search engine and tech company, Google. Did you know that the name was inspired by another very large number? Though the spelling is different, the googol and the googolplex did play a role in the naming of the tech giant.

A googol has 100 zeros and is expressed as 10100. It is often used to express any large quantity, even though it is a quantifiable number. It makes sense that the largest search engine which pulls a large quantity of data from the internet would find this word useful.

The term googol was coined by the American mathematician Edward Kasner in his 1940 book, "Mathematics and the Imagination." The story goes that Kasner asked his then 9-year-old nephew, Milton Sirotta, what to name this ridiculously long number.

Sirotta came up with googol.

But why is a googol important if it's actually less than a centillion? Quite simply, a googol is used to define a googoolplex. A googolplex is "10 to the power of googol," a number that boggles the mind. In fact, a googolplex is so large that there's really no known use for it yet. Some say that it even exceeds the total number of atoms in the universe.

The googolplex is not even the largest number defined to date. Mathematicians and scientists have also devised "Graham's number" and "Skewes number." Both of these require a math degree to even begin to understand.

The Short and Long Scales of a Billion

If you thought the concept of a googolplex is tricky, some people cannot even agree on what defines a billion.

In the U.S. and throughout most of the world, it is accepted that one-billion equals 1,000 million.

As we've seen, this is written as 1,000,000,000 or 109. We use this number all the time in science and finance and it is called the "short scale."

In the "long scale," one-billion is equal to 1 million million. For this number, you will need a 1 followed by 12 zeros: 1,000,000,000,000 or 1012. The long scale was first described by Genevieve Guitel in 1975. It is used in France and, until recently, accepted in the United Kingdom as well.