Q:
# How many digits of pi have been calculated?

A:
### Quick Answer

**According to Numberworld, 12.1 trillion digits of pi have been calculated, as of December 2013.** This was achieved after 94 days of computation; however, 12 of those days were lost to hardware issues. The previous calculation that achieved 10 trillion digits took 371 days to complete two years prior.

Credit:
The Washington Post
The Washington Post
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As of 2014, the world record for digits of pi memorized is held by Chao Lu from China. He spent four years practicing and was able to recite 67,890 digits of pi from memory. The recitation happened on Nov. 20, 2005, took just over 24 hours to complete and was documented on 26 video tapes.

Learn more about Numbers-
Q:
## What is standard notation?

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Full Answer >**Standard notation is when a number is completely written out using numerical digits.**Some examples of numbers written in standard notation are 64,100 and 2,000,000.Filed Under: -
Q:
## What is number and word notation?

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Full Answer >**In math, number and word notation is simply writing the significant digits of a large number and using words for the place value.**For example, the number 45,000 in number and word notation is 45 thousand.Filed Under: -
Q:
## What is the largest prime number?

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Full Answer >**The largest known prime number is equivalent to 2^(57,885,161) -1, and it is 17,425,170 digits long.**It was discovered on Jan. 25, 2013 at the University of Central Missouri.Filed Under: -
Q:
## How many digits are in pi?

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Full Answer >**An endless number of digits are in pi.**It is an irrational number, which means it cannot be expressed as the ratio of any two integers. Furthermore, it was proved in 1882 that pi is not the root of an algebraic equation that has rational factors.Filed Under: