Discover a lot of information on the number 18: properties, mathematical operations, how to write it, symbolism, numerology, representations and many other interesting things!

## Mathematical properties of 18

Questions and answers |

Is 18 a prime number? |
No |

Is 18 a perfect number? |
No |

Number of divisors |
6 |

List of dividers |
1, 2, 3, 6, 9, 18 |

Sum of divisors |
39 |

Prime factorization |
2 x 3^{2} |

Prime factors |
2, 3 |

## How to write / spell 18 in letters?

In letters, the number 18 is written as: Eighteen. And in other languages? how does it spell?

18 in other languages |

Write 18 in english |
Eighteen |

Write 18 in french |
Dix-huit |

Write 18 in spanish |
Dieciocho |

Write 18 in portuguese |
Dezoito |

## Decomposition of the number 18

The number 18 is composed of:

1 iteration **of the number 1** : The number 1 (one) represents the uniqueness, the unique, a starting point, a beginning.... Find out more about the number 1

1 iteration **of the number 8** : The number 8 (eight) represents power, ambition. It symbolizes balance, realization.... Find out more about the number 8

## Mathematical representations and links

Other ways to write 18 |

In letter |
Eighteen |

In roman numeral |
XVIII |

In binary |
10010 |

In octal |
22 |

In hexadecimal |
12 |

In US dollars |
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USD 18.00 ($) |

In euros |
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18,00 EUR (€) |

Some related numbers |

Previous number |
17 |

Next number |
19 |

Next prime number |
19 |

## Mathematical operations

Operations and solutions |

18*2 |
= |
36 |
The double of 18 is 36 |

18*3 |
= |
54 |
The triple of 18 is 54 |

18/2 |
= |
9 |
The half of 18 is 9.000000 |

18/3 |
= |
6 |
The third of 18 is 6.000000 |

18^{2} |
= |
324 |
The square of 18 is 324.000000 |

18^{3} |
= |
5832 |
The cube of 18 is 5832.000000 |

√18 |
= |
4.2426406871193 |
The square root of 18 is 4.242641 |

log(18) |
= |
2.8903717578962 |
The natural (Neperian) logarithm of 18 is 2.890372 |

log10(18) |
= |
1.2552725051033 |
The decimal logarithm (base 10) of 18 is 1.255273 |

sin(18) |
= |
-0.75098724677168 |
The sine of 18 is -0.750987 |

cos(18) |
= |
0.66031670824408 |
The cosine of 18 is 0.660317 |

tan(18) |
= |
-1.1373137123377 |
The tangent of 18 is -1.137314 |