Titanic Prime
In the 1980s, Samuel Yates defined a titanic prime to be a prime number of at least 1000 decimal digits. The smallest titanic prime is 
. As of 1990, more than 1400 were known (Ribenboim 1990). By 1995, more than 
were known, and many tens of thousands are known today. The largest prime number known as of December 2018 is the Mersenne prime 
, which has a whopping 
decimal digits.
REFERENCES:
Caldwell, C. "The Ten Largest Known Primes." https://www.utm.edu/research/primes/largest.html#largest.
Lifchitz, H. and Lifchitz, R. "PRP Records: Probable Primes Top 10000." https://www.primenumbers.net/prptop/prptop.php.
Mersenne Organization. "Titanic Primes Raced to Win $100,000 Research Award." Sep. 15, 2008. https://mersenne.org/m45and46.htm.
Morain, F. "Elliptic Curves, Primality Proving and Some Titanic Primes." Astérique 198-200, 245-251, 1992.
Ribenboim, P. The Little Book of Big Primes. Berlin: Springer-Verlag, p. 97, 1990.
Weisstein, E. W. "44th Mersenne Prime Found." MathWorld Headline News, Sep. 11, 2006. https://mathworld.wolfram.com/news/2006-09-11/mersenne-44/.
Yates, S. "Titanic Primes." J. Recr. Math. 16, 250-262, 1983-84.
Yates, S. "Sinkers of the Titanics." J. Recr. Math. 17, 268-274, 1984-85.
