Welcome to the dictionary of numbers

This page will tell you almost everything that it is necessary to know about number: 21
Let's begin with a basic information:

Number 21

Structure

Number 21 has 2 figures which are brought to 3. In English it sounds so: twenty-one. Besides, the numbers representing number 21 are: two, one.
Number 21 - decimal number which means that on the basis 10. 21 can be also presented in different bases, such as the Binary system of calculation also looks: 10101, the Octal system of an calculation also, also looks as and 16, in Hexadecimal system of calculation and looks as follows: . 21 The number in the triple system of reference looks like: in fourfold: 111 in pyatirichoy: in shestirichnoy: 33 in the septenary: . Also the number of number systems in from 4 to 34.

Characteristic

Number 21 is Positive and Odd. His inverse number 0,047619047619048 and negative number -21. Number 21 can be divided on 1, 3, 7, 21 without the rest. Besides, it is not an ideal square, and it not a prime number. Now let's use trigonometrical functions. By means of sinusoidal function: Sin(21°) gives 0,837, using function of the Cosine of the cos function (21°) gives -0,548 and through the Tangent the tan function(21°) is made by -1,527. Arctangent number is 21 1,523, area of ​​a circle of radius equal to 21 1385,442 exponent in powers of 21 is 1318815734,483.
Previous number: 20
Binary (base two): 10101
Number (base 4): 111
Number (base 6): 33
Number (base 8): 25
Number (base 10): 21
Number (base 12): 19
Number (base 14): 17
Number (base 16): 15
Number (base 18): 13
Number (base 20): 11
Number (base 22): l
Number (base 24): l
Number (base 26): l
Number (base 28): l
Number (base 30): l
Number (base 32): l
Number (base 34): l
Inverse: 0,047619047619048
Counter: -21
Divisible by: 1, 3, 7, 21
Factorial number: 5,1090942171709E+19
Number of digits: 2
Sum of digits: 3
Product of digits: 2
21 radian is equal (degree): 1203,211
Next number: 22
Number (base 3): 210
Number (base 5): 41
Number (base 7): 30
Number (base 9): 23
Number (base 11): 1a
Number (base 13): 18
Number (base 15): 16
Number (base 17): 14
Number (base 19): 12
Number (base 21): 10
Number (base 23): l
Number (base 25): l
Number (base 27): l
Number (base 29): l
Number (base 31): l
Number (base 33): l
Even / Odd: Odd
Unix Timestamp: Thu Jan 01 00:00:21 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
Atan: 1,523
Area of a circle r= 21: 1385,442
exhibitor (degree 21): 1318815734,483