A pi-prime is a prime number appearing in the decimal expansion of pi. The known examples are 3, 31, 314159, 31415926535897932384626433832795028841, ... (OEIS A005042). The numbers of digits in these examples are 1, 2, 6, 38, 16208, 47577, 78073, 613373, ... (OEIS A060421). The largest of these are summarized in the following table. decimal digits | discoverer | date 47577 | E. W. Weisstein | Apr. 1, 2006 78073 | E. W. Weisstein | Jul. 13, 2006 613373 | A. Bondrescu | May 29, 2016

constant primes | e-prime | integer sequence primes | phi-prime | pi