Mathematics 13 facts

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

2) 1089 multiplied by 9 gives an exact reverse: 9801.

3) From 0 to 1,000, the letter "A" only appears in 1,000 ("one thousand").
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. Sciensational.com


4) 1 × 9 + 2 = 11
12 × 9 + 3 = 111
123 × 9 + 4 = 1111
... and so on.

5)40 when written "forty" is the only number with letters in alphabetical order, while "one" is the only one with letters in reverse order.

6)Multiplication and succession: 142857 is a cyclic number, i.e., its digits are rotated around when multiplied by any number from 1 to 6. Like this:

7)142857 × 1 = 142857
142857 × 5 = 7 14285
142857 × 4 = 57 1428
142857 × 6 = 857 142
142857 × 2 = 2857 14
142857 × 3 = 42857 1


8) 1 × 8 + 1 = 9
12 × 8 + 2 = 98
123 × 8 + 3 = 987
and so on.

9)The opposite sides of a dice cube always add up to seven.

10)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.
11)2 and 5 are the only primes that end in 2 or 5.
12)The largest prime number is 9,808,358 digits long; more than the number of atoms in the universe. Sciensational.com

13)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.