Math facts & trivia - 1

2 is called the "oddest" Even Prime-number. 2 is a unique Even Prime because all Even-numbers are divisible by 2. But any number apart from 2 that is divisible by 2, is not a Prime.

1 x 9 + 2 = 11 12 x 9 + 3 = 111 123 x 9 + 4 = 1111
and so on. Submitted by: Rob

40 when written "forty" is the only number with letters in alphabetical order, while "one" is the only one with letters in reverse order. Submitted by: Rob

1 googol = 10¹⁰⁰;
1 googolplex = 10^googol = 10¹⁰¹⁰⁰ .

111 111 111 x 111 111 111 = 12345678 9 87654321

Pi (3.14159...) is a number that cannot be written as a fraction. Submitted by: Tiff - Witherbee, United States

The opposite sides of a dice cube always add up to seven. Submitted by: Ramesh -

21978 when multiplied by 4 is the same number with digits in reverse order: 21978 x 4 = 87912

If you add up the numbers 1-100 consecutively (1+2+3+4+5...) the total is 5050.

The billionth digit of Pi is 9.

1 and 2 are the only numbers where they are the values of the numbers of factors they have.

2 and 5 are the only primes that end in 2 or 5.

The largest prime number is 9,808,358 digits long; more than the number of atoms in the universe.

The digits to the right of the Pi's (3.141...) decimal point can keep going forever, and there is no pattern to these digits at all.