Prime Numbers: The Most Mysterious Figures in Math

The recent spate of popular books on the Riemann hypothesis, which concerns the distribution of prime numbers and is the greatest unsolved math problem since Andrew Wiles solved Fermat's famous last theorem 10 years ago, augurs well for this directory from British author Wells (The Penguin Dictionary of Curious and Interesting Numbers). Arranged alphabetically, the text covers such topics as gaps between primes, Mersenne primes (primes of the form 2 to the nth power minus 1), palindromic primes, record primes (the largest ""not of a special and easily tested form"" as of 2003 has 10,000 digits), repunits (primes that consist exclusively of the digit 1), ""sexy"" primes (primes that differ by six) and twin primes. For James Bond fans, there's even mention of ""007"" primes. Mathematicians who contributed to prime number theory, including Leonhard Euler, G.H. Hardy and A.M. Legendre, receive separate entries. While some of the math is fairly sophisticated, lay readers will find plenty that's readily comprehensible. A bibliography and list of Web sites point the way for those wishing to explore primes in greater depth.