Monday, September 22, 2008

23

23 is the ninth prime number, the smallest odd prime that is not a twin prime.

23 is one of only two integers that needs nine (positive) cubes to represent it: 23 = 23 + 23 + 13 + 13 + 13 + 13 + 13 + 13 + 13.

There were
23 problems on David Hilbert’s list of unsolved mathematical problems, presented to the International Congress of Mathematicians in Paris in 1900.

For
23 or more people in a room, the probability that two people have the same birthday is greater than 50%.

23! is 23 digits long.

The speed limit on campus at Tulane University.

Sources:
Number Gossip; Wikipedia
Photo: M. Pearson

2 comments:

mathletics said...

It is also the answer to the question, "How many sides does a polygon have if the number of diagonals is ten times the number of sides?"

pjcostello said...

The least common multiple of all the binomial coefficients on row 23 of Pascal's triangle is equal to the product of all the primes less than or equal to 23.