The number 21343
21343 is a composite number with 4 divisors. Its prime factorisation is 7 × 3049. Divisors (4): 1, 7, 3049, 21343.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21343: a semiprime: 7 × 3049, the product of two primes.
- 2
21343 is composite. Its prime factorisation is
- 3
The divisors add up to 24400; without 21343 itself that is 3057, so 21343 is deficient (3057 is less than 21343). Euler's totient φ(21343) = 18288 numbers up to 21343 share no factor with it.
- 4
The digits of 21343 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 87 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21343 = 7 \times 3049 \]
21343 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 24400 |
| Euler totient φ(n) | 18288 |
| Square | 455523649 |
| Cube | 9722241240607 |
| Square root | 146.092436 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 87 |
| Scientific notation | 2.1343 × |
21343 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand three hundred and forty-three |
| Binary (base 2) | 101001101011111 |
| Octal (base 8) | 51537 |
| Hexadecimal (base 16) | 535F |
| Base 3 | 1002021111 |
| As time | 21343 seconds = 5 h 55 min 43 s |
Is 21343 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 | No (remainder 1) | 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (21343 ÷ 7 = 3049) | 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 | No (remainder 4) | 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 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21343 a prime number?
No. 21343 = 7 × 3049, so it is divisible by 7.
What are the factors of 21343?
1, 7, 3049, 21343.
What is 21343 in binary?
101001101011111 (hexadecimal 535F, octal 51537).
What is the square root of 21343?
About 146.0924.
Is 21343 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 21343?
21343 is a semiprime: 7 × 3049, the product of two primes.