Megaprime

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A megaprime is a prime number with at least one million decimal digits. [1]

Other terms for large primes include "titanic prime", coined by Samuel Yates in the 1980s for a prime with at least 1000 digits [2] (of which the smallest is 10999+7), [3] and "gigantic prime" for a prime with at least 10,000 digits [4] (of which the smallest is 109999+33603). [5]

Number of megaprimes found by year through 2023 Megaprimes found by year.png
Number of megaprimes found by year through 2023

As of 24 October 2024, there are 2,864 known megaprimes [6] which have more than 1,000,000 digits. [7] The first to be found was the Mersenne prime 26972593−1 with 2,098,960 digits, discovered in 1999 by Nayan Hajratwala, a participant in the distributed computing project GIMPS. [8] [9] 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, and there is a very high probability that 10999999 + 593499, a strong probable prime for each of 8 different bases, is the smallest megaprime. [10] As of 2022, 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. [11] [12] [13]

See also

Related Research Articles

<span class="mw-page-title-main">Great Internet Mersenne Prime Search</span> Volunteer project using software to search for Mersenne prime numbers

The Great Internet Mersenne Prime Search (GIMPS) is a collaborative project of volunteers who use freely available software to search for Mersenne prime numbers.

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 Mn = 2n − 1 for some integer n. They are named after Marin Mersenne, a French Minim friar, who studied them in the early 17th century. If n is a composite number then so is 2n − 1. Therefore, an equivalent definition of the Mersenne primes is that they are the prime numbers of the form Mp = 2p − 1 for some prime p.

In recreational mathematics, a repunit is a number like 11, 111, or 1111 that contains only the digit 1 — a more specific type of repdigit. The term stands for "repeated unit" and was coined in 1966 by Albert H. Beiler in his book Recreations in the Theory of Numbers.

In recreational mathematics, a repdigit or sometimes monodigit is a natural number composed of repeated instances of the same digit in a positional number system. The word is a portmanteau of "repeated" and "digit". Examples are 11, 666, 4444, and 999999. All repdigits are palindromic numbers and are multiples of repunits. Other well-known repdigits include the repunit primes and in particular the Mersenne primes.

This list contains selected positive numbers in increasing order, including counts of things, dimensionless quantities and probabilities. Each number is given a name in the short scale, which is used in English-speaking countries, as well as a name in the long scale, which is used in some of the countries that do not have English as their national language.

73 (seventy-three) is the natural number following 72 and preceding 74. In English, it is the smallest natural number with twelve letters in its spelled out name.

In mathematics, a palindromic prime is a prime number that is also a palindromic number. Palindromicity depends on the base of the number system and its notational conventions, while primality is independent of such concerns. The first few decimal palindromic primes are:

<span class="mw-page-title-main">PrimePages</span> Website about prime numbers

The PrimePages is a website about prime numbers originally created by Chris Caldwell at the University of Tennessee at Martin who maintained it from 1994 to 2023.

100,000 (one hundred thousand) is the natural number following 99,999 and preceding 100,001. In scientific notation, it is written as 105.

<span class="mw-page-title-main">Largest known prime number</span>

The largest known prime number is 2136,279,841 − 1, a number which has 41,024,320 digits when written in base 10. It was found on October 12, 2024 by a computer volunteered by Luke Durant to the Great Internet Mersenne Prime Search (GIMPS).

In mathematics, a pandigital number is an integer that in a given base has among its significant digits each digit used in the base at least once. For example, 1234567890 is a pandigital number in base 10.

In number theory, a Leyland number is a number of the form

Industrial-grade primes are integers for which primality has not been certified, but they have undergone probable prime tests such as the Miller–Rabin primality test, which has a positive, but negligible, failure rate, or the Baillie–PSW primality test, which no composites are known to pass.

In number theory, a left-truncatable prime is a prime number which, in a given base, contains no 0, and if the leading ("left") digit is successively removed, then all resulting numbers are prime. For example, 9137, since 9137, 137, 37 and 7 are all prime. Decimal representation is often assumed and always used in this article.

In number theory, a prime triplet is a set of three prime numbers in which the smallest and largest of the three differ by 6. In particular, the sets must have the form (p, p + 2, p + 6) or (p, p + 4, p + 6). With the exceptions of (2, 3, 5) and (3, 5, 7), this is the closest possible grouping of three prime numbers, since one of every three sequential odd numbers is a multiple of three, and hence not prime (except for 3 itself).

In recreational number theory, a minimal prime is a prime number for which there is no shorter subsequence of its digits in a given base that form a prime. In base 10 there are exactly 26 minimal primes:

In number theory, primes in arithmetic progression are any sequence of at least three prime numbers that are consecutive terms in an arithmetic progression. An example is the sequence of primes, which is given by for .

43,112,609 is the natural number following 43,112,608 and preceding 43,112,610.

References

  1. Chris Caldwell, The Prime Glossary: megaprime at The PrimePages. Retrieved on 2008-01-04.
  2. Chris Caldwell, The Prime Glossary: titanic prime at The PrimePages. Retrieved on 2022-06-21.
  3. "factordb.com". factordb.com.
  4. Chris Caldwell, The Prime Glossary: gigantic prime at The PrimePages. Retrieved on 2022-06-21.
  5. "factordb.com". factordb.com.
  6. Chris Caldwell, The Largest Known Primes at The PrimePages.
  7. Henri Lifchitz & Renaud Lifchitz, Probable Primes Top 10000, primenumbers.net
  8. GIMPS press release, GIMPS Finds First Million-Digit Prime. Retrieved on 2008-01-04.
  9. Chris Caldwell, The Largest Known Prime by Year: A Brief History at The PrimePages. Retrieved on 2008-09-28.
  10. Patrick De Geest, 10^999999 + y, World!Of Numbers
  11. Henri Lifchitz & Renaud Lifchitz, Probable Primes search for 10^999999-a, primenumbers.net
  12. Patrick De Geest, Border Probable Primes around 'Powers of Ten', worldofnumbers.com
  13. Sloane, N. J. A. (ed.). "SequenceA340902(Distance from the largest prime with less than 10^n decimal digits to 10^(10^n-1))". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.