Question 398214
I don't know of a standard.
Some numbers, such as pi, are thought to be irrational and have been checked to 2 million digits (maybe more), but there's no proof that it won't start to repeat at some point.
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What is it you want to figure out?
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I checked on google, found this:
The record for the number of digits of pi calculated is held by a 55-year-old Japanese programmer.  A program writte by Shieguru Kondo calculated 5 trillion digits of pi, taking 90 days.