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 (10

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

© Jo Edkins 2018 - Return to Puzzles index