# Number 21

#### Feature

The number 21 is a Positive and Odd number. it's Inverse number is 0.047619047619048 and it's Counter number is -21. The number 21 can be divided by 1 ,3 ,7 ,21 without remainder of course. In addition, it's not a Perfect square and it's not a Prime number.Now Let's use some trigonometric functions just for fun... Using the Sine Fuction: Sin(21°) gives 0.837, using the Cosine Function Cos(21°) gives -0.548 and using the Tangent Function tan(21°) gives -1.527.

#### Structure

21 contains 2 digits that summed up to 3. .In English this number should sounds like: twenty-one. In addition, the digits that represents the number 21 are: two ,one.
The number 21 is a decimal number and it means that it represented in base 10. 21 can also be represented In different bases such as base two, that also known as Binary and looks like: 10101, base 8, that also known as Octal and looks like 25 and base 16, that also known as Hexadecimal and looks like: 15. These are the the most common bases but of course, there are much more bases.

#### Possible Meanings for the number:

This number can represent an IP address such as: 0.0.2.1 This number can also represents a webcolor like : #000021

#### More Fibonacci Numbers

 Previous number 20 Binary (base two): 10101 Octal (base 8): 25 Hexadecimal (base 16): 15 Inverse: 0.047619047619048 Counter: -21 Divisible by: 1 ,3 ,7 ,21 Factorial number: 5.1090942171709E+19 Number of digits: 2 Prime Factorization: 3,7 Sum of digits: 3 This number can be ip : 0.0.2.1
 Next number 22 Even / Odd: Odd Unix Timestamp: Thu Jan 1 2:00:21 1970 Perfect square: NO Prime: NO Positive / Negative: Positive English: twenty-one English digits: two ,one Sin: 0.837 Cos: -0.548 Tan: -1.527 Color Number: #000021 Fibonacci number: YES

#### Do you have any other meaning for this number? share it! tell us what you have on this special number:

WhatÂ´s 9 plus 10? - 21.

Updated at : 25/01/2016
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