A megaprime is a

prime number A prime number (or a prime) is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways ...

with at least one million decimal digits. Other terms for large primes include titanic prime, coined by

Samuel Yates Samuel Yates (May 10, 1919 in Savannah, Georgia – April 22, 1991 in New Brunswick, New Jersey) was a computer engineer and mathematician who first described unique primes in the 1980s. In 1984 he began the list of "Largest Known Primes" (today Th ...

in the 1980s for a prime with at least 1000 digits, and gigantic prime for a prime with at least 10,000 digits. Bevaprime has been proposed for a prime with at least 1,000,000,000 digits. , there are more than 1500 known megaprimesChris Caldwell
The Largest Known Primes
at The PrimePages. and 85 further

probable prime In number theory, a probable prime (PRP) is an integer that satisfies a specific condition that is satisfied by all prime numbers, but which is not satisfied by most composite numbers. Different types of probable primes have different specific con ...

s (PRPs) which have more than 1,000,000 digits.Henri Lifchitz & Renaud Lifchitz, Probable Primes Top 10000
primenumbers.net The first to be found was the

Mersenne prime In mathematics, a Mersenne prime is a prime number that is one less than a power of two. That is, it is a prime number of the form for some integer . They are named after Marin Mersenne, a French Minim friar, who studied them in the early 17th ...

2^6972593−1 with 2,098,960 digits, discovered in 1999 by Nayan Hajratwala, a participant in the

distributed computing A distributed system is a system whose components are located on different networked computers, which communicate and coordinate their actions by passing messages to one another from any system. Distributed computing is a field of computer sci ...

project

GIMPS The Great Internet Mersenne Prime Search (GIMPS) is a collaborative project of volunteers who use freely available software to search for Mersenne prime numbers. GIMPS was founded in 1996 by George Woltman, who also wrote the Prime95 client an ...

press release
''GIMPS Finds First Million-Digit Prime''
Retrieved on 2008-01-04.Chris Caldwell

at The PrimePages. Retrieved on 2008-09-28. Nayan was awarded a Cooperative Computing Award from the Electronic Frontier Foundation for this achievement. Almost all primes are megaprimes, as the number of primes with fewer than one million digits is finite. However, the vast majority of known primes are not megaprimes. All numbers from 10⁹⁹⁹⁹⁹⁹ through 10⁹⁹⁹⁹⁹⁹ + 593498 are known to be

composite Composite or compositing may refer to: Materials * Composite material, a material that is made from several different substances ** Metal matrix composite, composed of metal and other parts ** Cermet, a composite of ceramic and metallic materials ...

, and there is a very high probability that 10⁹⁹⁹⁹⁹⁹ + 593499, a strong probable prime, is the smallest megaprime.Patrick De Geest
10^999999 + y
World!Of Numbers , the smallest number known to be a megaprime is 10⁹⁹⁹⁹⁹⁹ + 308267*10²⁹²⁰⁰⁰ + 1. The last prime that is not a megaprime is almost certainly 10⁹⁹⁹⁹⁹⁹ - 172473.

References

{{Large numbers Prime numbers Large integers

See also

References