The number 21303
21303 is a composite number with 10 divisors. Its prime factorisation is × 263. Divisors (10): 1, 3, 9, 27, 81, 263, 789, 2367, 7101, 21303.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21303: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 9.
- 2
21303 is composite. Its prime factorisation is
- 3
The divisors add up to 31944; without 21303 itself that is 10641, so 21303 is deficient (10641 is less than 21303). Euler's totient φ(21303) = 14148 numbers up to 21303 share no factor with it.
- 4
The digits of 21303 add up to 9, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 100 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21303 = 3^{4} \times 263 \]21303 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 10 |
| Sum of divisors | 31944 |
| Euler totient φ(n) | 14148 |
| Square | 453817809 |
| Cube | 9667680785127 |
| Square root | 145.955473 (= 9√263) |
| Digit sum / digital root | 9 / 9 |
| Collatz steps to 1 | 100 |
| Scientific notation | 2.1303 × |
21303 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand three hundred and three |
| Binary (base 2) | 101001100110111 |
| Octal (base 8) | 51467 |
| Hexadecimal (base 16) | 5337 |
| Base 3 | 1002020000 |
| As time | 21303 seconds = 5 h 55 min 3 s |
Is 21303 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21303 ÷ 3 = 7101) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | A number is divisible by 7 if double the last digit and subtract it from the rest: the result is a multiple of 7. |
| 8 | No (remainder 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (21303 ÷ 9 = 2367) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 3) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21303 a prime number?
No. 21303 = × 263, so it is divisible by 3.
What are the factors of 21303?
1, 3, 9, 27, 81, 263, 789, 2367, 7101, 21303.
What is 21303 in binary?
101001100110111 (hexadecimal 5337, octal 51467).
What is the square root of 21303?
About 145.9555, exactly 9√263.
Is 21303 divisible by 3?
Yes. Its digits add up to 9, a multiple of 3.
What is special about the number 21303?
21303 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 9.