Science, Maths & Technology

# A prime primer

Updated Thursday 15th September 2005

They're astonishingly powerful numbers. Simon Singh introduces the primes.

Mathematicians love prime numbers in much the same way that chemists love atoms and biologists love genes. Just as atoms are the building blocks of the matter around us and genes are the building blocks of life, prime numbers are the building blocks of mathematics.

Hence, the study of prime numbers has had a tremendous impact on everything from illuminating unexplored areas of pure mathematics to inspiring new technologies for protecting our most secret communications.

Prime numbers, for those who have forgotten, are those numbers that cannot be divided by any other number except 1 and itself. So 5 is prime because nothing will divide into it, but 6 is not prime because it can be divided by 2 and 3. All numbers can be broken down into a series of one or more primes multiplied together, so the prime 5 is just 5, while 6 is 2

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