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Do you know how to write 21 in words? It is written as twenty-one in English. It is a natural number which comes between 20 and 22. It is an odd and composite number which have two digits, namely ones and tens. This number can be used to count in real-life situations. For example, if there are 21 balls in a jar, it can be written as there are twenty-one balls in a jar. This number can also be used for the currency, for example, Twenty-one rupees. In this section, we will discuss ow to write 21 in words. This type of subject helps children learn the fundamental concept of numbers in a more detailed and simple way. Keep reading to learn more.
Table of Contents
21 in Words in English
In words, 21 is expressed as “twenty-one.” It is a two-digit number with place value of ones and tens. It holds many important properties. Some important properties related to number 21 are mentioned below:
| Properties | Explanation | |
| Is 21 a natural number? | Yes | 21 is a natural number as it is a positive counting number. |
| Is 21 an odd number? | Yes | 21 is not divisible by 2. |
| Is 21 an even number? | No | 21 is not divisible by 2. |
| Is 21 a perfect square number? | No | There is no such number which when multiplied by itself gives 21. |
| Is 21 a perfect cube number? | No | 21is not a perfect cube as it cannot be written as a product of three equal integers. |
| Is 21 a prime number? | No | 21 is not a prime number as it has more than 2 factors: 1, 3, 7 and 21. |
| Is 21 a composite number? | Yes | 21 is a composite number as it has more than two factors: 1, 3, 7 and 21. |
How to Convert 21 in Words?
21 is a number with a specific written form (“twenty-one”) derived from its place values. Let’s convert 21 in words in English:
| Hundreds | Tens | Ones |
| 21 | 2 | 1 |
Step 1: Identify the numbers of digits.
Here, as we can see 21 is a two-digit number, which means that it has two-place values, namely ones and tens.
Step 2: Write in expanded form.
= 2 x Tens + 1 x Ones
= 2 x 10 + 1 x 1
= 20 +1
= 21
= Twenty-one
Therefore, 21 can be written as Twenty-one.
Hence, once you understand the place value of the digit, it will be easier for you to write it in words or expanded form.
Rules to Write Numbers in English
Numbers can be tricky in English. Here we have mentioned simple steps to help you write them effectively:
- Small Numbers (1-9): Spell out numbers one through nine in most contexts (e.g., five apples, seven days).
- Larger Numbers (10+): Use numerals (numbers as digits) for numbers ten and above (e.g., 12 o’clock, 35 kilometres).
- Sentence Starters: Always spell out a number that begins a sentence, regardless of size (e.g., Twenty-three guests arrived).
- Numbers in Phrases: Certain common phrases might use spelt-out numbers even for larger values (e.g., a hundred years, two dozen eggs).
Facts of Number 21
We’ve written a few facts related to the number 21. It will let you learn some interesting facts about this digit.
- 21 is the atomic number of Scandium, an element.
- In some countries, 21 marks the legal age for activities like drinking, gambling or purchasing firearms.
- 21 is significant in some sports – the number of points needed to win in 3×3 basketball or the squad size in AFL Women’s.
- The number 21 is associated with card games like Blackjack where achieving 21 points wins.
1 to 21 Numbers in Words
A number names chart (1-21 can be a helpful tool for children learning to spell numbers). They can practice by calling out numbers they see around them, making learning fun and interactive.
| Number | Word | Number | Word | Number | Word |
| 1 | One | 8 | Eight | 15 | Fifteen |
| 2 | Two | 9 | Nine | 16 | Sixteen |
| 3 | Three | 10 | Ten | 17 | Seventeen |
| 4 | Four | 11 | Eleven | 18 | Eighteen |
| 5 | Five | 12 | Twelve | 19 | Nineteen |
| 6 | Six | 13 | Thirteen | 20 | Twenty |
| 7 | Seven | 14 | Fourteen | 21 | Twenty-one |
FAQs
21 in words is written as twenty-one.
21 to 30 in words: Twenty-one, twenty-two, twenty-three, twenty-four, twenty-five, twenty-six, twenty-seven, twenty-eight, twenty-nine, thirty.
22 in words is written as twenty-two.
21 rupees is spelled as twenty-one rupees
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