Prime number
positive integer with exactly two divisors, 1 and itself / From Wikipedia, the free encyclopedia
A prime number is a natural number of a particular kind. Any natural number is equal to 1 times itself. If the number is equal to any other natural numbers multiplied, then the number is called a composite number. The smallest composite number is 4, because 2 x 2 = 4. 1 is not a composite number. Every other number is a prime number. The prime numbers are the numbers other than 1 which are not equal to (except 1 times itself).[1] The smallest prime number is 2. The next prime numbers are 3, 5, 7, 11, and 13. There is no largest prime number. The set of prime numbers is sometimes written as .[2]
The fundamental theorem of arithmetic states that every positive integer can be written as a product of primes in a unique way,[3] though the way the prime numbers occur is a difficult problem for mathematicians. When a number is larger, it is more difficult to know if it is a prime number. One of the answers is the prime number theorem. One of the unsolved problems is Goldbach's conjecture.
One of the most famous mathematicians of the classical era, Euclid, recorded a proof that there is no largest prime number. However many scientists and mathematicians are still searching to find it as part of the Great Internet Mersenne Prime Search.