Prime numbers


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To see more about some other numbers click here.

Think that numbers are boring? Well then there must be a smallest of all the boring numbers. This will make it very interesting!

Primes are called the building blocks of integers - this is because an integer is either a prime, or can be written as a product of primes. But what is a prime number? It is a number which can only be divided by itself and 1. Some mathematicians thought that 1 was a prime too, but nowdays we say that 1 does not fall into the category of primes.

Is that all there is to it? Not at all! There are many interesting facts about primes, and many interesting stories about how mathematicians throughout the history tried to describe primes with a pattern or a formula.

Some of these formulas work partially - in other words they work in some cases, but don't work in others.

Click here to see some interesting primes.

Click here to see Euclid's proof of the infinity of primes.



Main number page

Prime numbers

Largest Prime Number known

See Eratosthenes' Prime Number sieve and download some worksheets: 100, 200 or 500 number sieve.

What people thought of primes through the history

Prime number (as the one defined by Aristotle, Euclid and Theon of Smyrna) is a number "measured by no number but by an unit alone" Iambilicus said that a prime number is also called "odd times odd".

Prime number was apparently first described by Pythagoras.

Iamblichus writes that Thymaridas called a prime number rectilinear since it can only be represented one-dimensionally.

In English prime number is found in Sir Henry Billingsley's 1570 translation of Euclid's Elements (OED2).

Some older textbooks include 1 as a prime number.

In his Algebra (1770), Euler did not consider 1 a prime [William C. Waterhouse].



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