# Curiosities

Magic Number

1089 is known as the magic number. Here's why:
Choose any three-digit number different: for example, 875.
Now write this number backwards and subtract the smaller more:
875-578 = 297
Now reverse this result and also do the sum:
297 + 792 = 1089 (the magic number)
Warning: before you send...

Curiosity with Three Digit Numbers

Choose a three-digit number:
Ex: 234
Repeat this number in front of it:
234234
Now divide by 13:
234234/13 = 18018
Now divide by 11:
18018/11 = 1638
Divide the result again, only now for 7:
1638/7 = 234
The result equals the number of three digits that you had chosen: 234....

Cyclic Numbers

The numbers are cyclic those multiplied by another number less than or equal to the number of digits that he has, his numbers will repeat cyclically, reaching the end those in front. For example: The first number is the cyclic 142,857. If this number (which has six digits) is multiplied by the numbe...

Mersenne Numbers

Are integers of the form Mp = 2p -1. If Mp is a prime number, the number P is also. Only 33 are known Mersenne numbers. The last discovered corresponds p = 859 433, which is the Mersenne number 2859433 -1.
It is not known whether there are an infinite number of them....

Golden Number

The golden ratio, golden number, golden number or golden ratio is an irrational algebraic real constant denoted by the Greek letter phi (PHI), in honor of Phideas sculptor (Phidias), that would have used to design the Parthenon, and the value (1.618033989 ...) rounded to three decimal places of 1.61...