Puzzles index

Interesting


These are not puzzles, just interesting facts!


The first nine prime numbers add up to 100. (2, 3, 5, 7, 11, 13, 17, 19, 23)


37 is the 12th prime number and 73 is the 21st prime number.


The following fractions produce these decimals. The different versions are because the results start overlapping, so the more complex fraction means they overlap further on.

1/81, 1/9801, 1/998001: positive integers in order

1/89, 1/9899, 1/998999: Fibonacci numbers

1/98, 1/998, 1/9998: powers of 2
1/97, 1/997, 1/9997: powers of 3
etc.

101/970299, 1001/997002999, 10001/999700029999: square numbers
1/970299, 1/997002999: triangular numbers



Belphegor's prime is the palindromic prime number 1 000 000 000 000 066 600 000 000 000 001 (1030 + 666 x 1014 + 1), a number which reads the same both backwards and forwards and is only divisible by itself and one. The name Belphegor refers to one of the Seven Princes of Hell, who was charged with helping people make ingenious inventions and discoveries. "Belphegor's prime" is a name coined by author Clifford A. Pickover. The number itself contains superstitious elements that have given it its name: the number 666 at the heart of Belphegor's Prime is widely associated as being the Number of the Beast, used in symbolism to represent one of the creatures in the Apocalypse or, more commonly, the Devil. This number is surrounded on either side by thirteen zeroes and is 31 digits in length (thirteen reversed).



In English, the name of every number shares a letter with the next one. 1 shares "o" with 2, which shares "t" with three, and so on, to infinity.

This is less impressive than it sounds, since all numbers from 13-99 contain "teen" or "ty". Numbers from 100-999 contain "hundred". Numbers from 1000-999,999 contain thousand. Numbers after that contain "million" or some number ending "illion". 99, 100, 1000, 1,000,000 all contain "n".



This is a limerick:

(12 + 144 + 20 + 3 sqr4) / 7 + (5 x 11) = 9 power 2 + 0

Well, it is if you say it this way!

      A dozen, a gross and a score
      Plus three times the square root of four
      Divided by seven
      Plus five times eleven
      Is nine squared and not a bit more