One of the siblings posted a link from JPL about the number of digits they use for their highest precision calculations. In that article they also state that 37 decimals would be sufficient for calculating the cirumference of the observable universe down to the accuracy of the diameter of a hydrogen atom.[0]

[0] https://www.jpl.nasa.gov/edu/news/2016/3/16/how-many-decimal... (Right before the last inline image)