A Google engineer named Emma Haruka Iwao has calculated pi to 31 trillion digits, breaking the world record.

Pi is an infinite number essential to engineering.

She ran her calculations over Google's cloud service, marking another world first.

The calculation took about four months, or 121 days.

A Google employee named Emma Haruka Iwao has used Google's cloud-computing service to break the world record for calculating pi, an infinite number vital to engineering.

Most people will be familiar with the first few digits of pi from geometry class (3.14...). It's the number you get when you divide a circle's circumference by its diameter.

Iwao — a cloud developer advocate who has been working at Google for over three years — successfully calculated pi to 31 trillion digits, beating the previous record by 9 trillion. Google announced her accomplishment on Thursday, which just so happens to be Pi Day (March 14, or 3/14).

The calculation required huge amounts of data processing. Using the program y-cruncher on a Google Compute Engine cluster, she ate through 170 terabytes of data over about four months. To give a sense of scale, the BBC writes that roughly 200,000 music tracks total just 1 terabyte.

You can watch Iwao explain how she calculated pi here:

You can also read Google's technical explanation here.

Iwao says this is the first time cloud computing has been used to calculate pi and break the record. A Yahoo engineer used the company's cloud tech in 2010 to calculate the 2 quadrillionth digit of pi but did not calculate all the numbers in between.

Iwao told the BBC she's not done with pi. "There is no end with pi — I would love to try with more digits," she said.