Number 21 is said 🔊, write in letters as follows: twenty-one . Ordinal number 21th is said 🔊 and write: twenty-first. The meaning of number 21: Basic maths, advanced mathematics and properties, computer science, numerology, codes and images, writing and naming in other languages, other interesting facts and comments. Number 21 in News.
Useful information about number 21
|The number 21 converted to a Mayan number is|
|Decimal and Mayan number conversions.|
21 kilograms (kg) = 46.3 pounds (lb)
21 pounds (lb) = 9.5 kilograms (kg)
21 kilometers (km) equals to 13.049 miles (mi).
21 miles (mi) equals to 33.796 kilometers (km).
21 meters (m) equals to 33.796 feet (ft).
21 feet (ft) equals 6.401 meters (m).
21 centimeters (cm) equals to 8.3 inches (in).
21 inches (in) equals to 53.3 centimeters (cm).
21° Fahrenheit (°F) equals to 69.8° Celsius (°C)
21° Celsius (°C) equals to -6.1° Fahrenheit (°F)
21 Horsepower (hp) equals to 15.44 kilowatts (kW)
21 kilowatts (kW) equals to 28.56 horsepower (hp)
Codes and images of the number 21Number 21 morse code: ..--- .----
Sign language for number 21:
|Images of the number|
|Image (1) of the number||Image (2) of the number|
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Number 21 infographic.
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Gregorian, Hebrew, Islamic, Persian and Buddhist year (calendar)Gregorian year 21 is Buddhist year 564.
Buddhist year 21 is Gregorian year 522 a. C.
Gregorian year 21 is Islamic year -620 or -618.
Islamic year 21 is Gregorian year 641 or 642.
Gregorian year 21 is Persian year -602 or -601.
Persian year 21 is Gregorian 642 or 643.
Gregorian year 21 is Hebrew year 3781 or 3782.
Hebrew year 21 is Gregorian year 3739 a. C.
The Buddhist calendar is used in Sri Lanka, Cambodia, Laos, Thailand, and Burma. The Persian calendar is official in Iran and Afghanistan.
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Mathematics of no. 21
Multiplication table of 21
21 multiplied by two equals 42 (21 x 2 = 42).
21 multiplied by three equals 63 (21 x 3 = 63).
21 multiplied by four equals 84 (21 x 4 = 84).
21 multiplied by five equals 105 (21 x 5 = 105).
show multiplications by 6, 7, 8, 9 ...
Fractions: decimal fraction and common fraction
Fraction table of 21
Half of 21 is 10,5 (21 / 2 = 10,5 = 10 1/2).
One third of 21 is 7 (21 / 3 = 7).
One quarter of 21 is 5,25 (21 / 4 = 5,25 = 5 1/4).
One fifth of 21 is 4,2 (21 / 5 = 4,2 = 4 1/5).
show fractions by 6, 7, 8, 9 ...
Advanced math operations
The number 21 is not a prime number. The closest prime numbers are 19, 23.
21th prime number in order is 73.
Factorization and dividers
Factorization 3 * 7 = 21
Divisors of number 21 are 1 , 3 , 7 , 21
Total Divisors 4.
Sum of Divisors 32.
The second power of 212 is 441.
The third power of 213 is 9.261.
The square root √21 is 4,582576.
The cube root of 3√21 is 2,758924.
The natural logarithm of No. ln 21 = loge 21 = 3,044522.
The logarithm to base 10 of No. log10 21 = 1,322219.
The Napierian logarithm of No. log1/e 21 = -3,044522.
Trigonometric functionsThe cosine of 21 is -0,547729.
The sine of 21 is 0,836656.
The tangent of 21 is -1,527499.
Properties of the number 21Is a Friedman number: No
Is a Fibonacci number: Yes
Is a Bell number: No
Is a palindromic number: No
Is a pentagonal number: No
Is a perfect number: No
Number 21 in Computer Science
|Code type||Code value|
|Port 21/TCP||FTP Protocol (control) - port for FTP commands and flow control|
|Unix time||Unix time 21 is equal to Thursday Jan. 1, 1970, 12:21 a.m. GMT|
|IPv4, IPv6||Number 21 internet address in dotted format v4 0.0.0.21, v6 ::15|
|21 Decimal||= 10101 Binary|
|21 Decimal||= 210 Ternary|
|21 Decimal||= 25 Octal|
|21 Decimal||= 15 Hexadecimal (0x15 hex)|
|More SHA codes related to the number 21 ...|
The meaning of the number 2 (two), numerology 2
Character frequency 2: 1
The meaning of the number 1 (one), numerology 1
Character frequency 1: 1
Interesting facts about the number 21
- (21) Lutetia is asteroid number 21. It was discovered by H. M. S. Goldschmidt from Paris on 11/15/1852.
Aircrafts and flights
- 07/08/1965 the Canadian Pacific Air Lines plane, flight number 21, Douglas DC-6B crashed in near 100 Mile House, BC, Canada 46 passengers and 6 crew members died.
Areas, mountains and surfaces
- The total area of Nauru is 8.1 square miles (21 km²)
- The total area of Hokkaido is 30,394 square miles (78,719 square km). Country Japan (Hokkaido region). 21th largest island in the world.
- It is one of the lucky numbers for the zodiac sign Aries and Scorpio.
- ¿Qué es la astrología y para qué sirve?
Distances between cities
- There is a 14 miles (21 km) direct distance between Bogor (Indonesia) and Depok (Indonesia).
- There is a 14 miles (21 km) direct distance between Dombivli (India) and Navi Mumbai (India).
- There is a 14 miles (21 km) direct distance between Ecatepec (Mexico) and Mexico City (Mexico).
- 21 is a player's highest score in a hand of Blackjack or Twenty-one.
In other fields
- Dreaming of the number 21 means transmuting all of the above for spiritual balance, if this number repeats itself in time it is a good sign that you are achieving it.
- 21 is the smallest number of distinct squares needed to tile a square.
- '21 Seconds' is a song from the acronym of the British garage So Solid Crew.
- '21 Questions ', in Spanish '21 questions', is a song performed by 50 Cent, an American rapper and businessman.
- '21' is the debut single from The Paddingtons. '21' is also a song recorded by American singer Hunter Hayes.
- '21 Guns ', in Spanish '21 armas de fuego', is a song by the American punk rock band Green Day.
- '21 (Moon Water) 'is a song by the North American indie band Bon Iver.
- '21 Summer ', in Spanish '21 Verano', is a song by the American country music duo Brothers Osborne.
- '21 Savage 'is an American rapper, singer and songwriter. His name is Shyjah Joseph (Decatur, Georgia, October 22, 1992).
- Scandium is the chemical element in the periodic table that has the symbol Sc and atomic number 21.
- The best athletes to wear number 21
Roberto Clemente, MLB; Tim Duncan, NBA; Warren Spahn, MLB; LaDainian Tomlinson, NFL; Sammy Sosa, MLB; David Pearson, NASCAR; Roger Clemens, MLB; Deion Sanders, NFL
Tv, movies and cinematography
- Movie: 21 Days Together Year: 1940 Runtime: 72 Director: Basil Dean With: Vivien Leigh; Leslie banks
- Film: 21 Grams (21 Grams) Year: 2003 Duration: 125 Director: Alejandro González Inárritu With: Sean Penn; Benicio, the bull
- Film: '21 blackjack '(English title: 21) is a 2008 film directed by Robert Luketic and starring Jim Sturgess, Kevin Spacey, Kate Bosworth and Laurence Fishburne.
Please write usIf you know something interesting about the number 21 or any natural number (positive integer), please write to us.
Number 21 in other languages
|Spanish:||🔊 (número 21)|
|German:||🔊 (Anzahl 21)|
|French:||🔊 (nombre 21)|
vingt et un
|Portuguese:||🔊 (número 21)|
vinte e um
|Chinese:||🔊 (数 21)|
|Other languages ...|
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Number 21 in News
|BBC: Lockdown easing: Four numbers to look for ahead of the 21 June decision
The key numbers that offer clues as to whether "freedom day" will proceed as planned on 21 June. ...
June 8, 2021
|BBC: Covid-19: Hospital data key to 21 June lockdown end, says Raab
Dominic Raab says the decision depends on breaking the link between cases and hospital admissions. ...
June 13, 2021
|CNN: Ghana court denies bail for 21 detained LGBT activists
A Ghanaian court on Tuesday denied bail to 21 gay rights activists arrested nearly three weeks ago for what police described as an unlawful gathering, their lawyer said. ...
June 9, 2021
|BBC: Covid-19: Government 'open' to delaying 21 June England lockdown end date
Matt Hancock says 21 June is a "not before" date for ending England's remaining restrictions. ...
June 6, 2021
|BBC: Covid-19: Could a third wave change 21 June plans in England?
Rising coronavirus cases have called the planned 21 June relaxing of rules in England into question. ...
June 2, 2021