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Belphegor's prime number Belphegor's prime number is a palindromic prime number with a 666 hiding between 13 zeros and a 1 on either side. The ominous number can be abbreviated as 1 0(13) 666 0(13) 1, where the (13) denotes the number of zeros between the 1 and 666. Although he didn't "discover" the number, scientist and author Cliff Pickover made the sinister-feeling number famous when he named it after Belphegor (or Beelphegor), one of the seven demon princes of hell. The number apparently even has its own devilish symbol, which looks like an upside-down symbol for pi. According to...

A previously unnoticed property of prime numbers seems to violate a longstanding assumption about how they behave. o mathematicians have uncovered a simple, previously unnoticed property of prime numbers — those numbers that are divisible only by 1 and themselves. Prime numbers, it seems, have decided preferences about the final digits of the primes that immediately follow them. Among the first billion prime numbers, for instance, a prime ending in 9 is almost 65 percent more likely to be followed by a prime ending in 1 than another prime ending in 9. In a paper posted online today, Kannan Soundararajan...

LOS ANGELES (AP) -- Mathematicians at UCLA have discovered a 13-million-digit prime number, a long-sought milestone that makes them eligible for a $100,000 prize. The group found the 46th known Mersenne prime last month on a network of 75 computers running Windows XP. The number was verified by a different computer system running a different algorithm. "We're delighted," said UCLA's Edson Smith, the leader of the effort. "Now we're looking for the next one, despite the odds." It's the eighth Mersenne prime discovered at UCLA.