The number 23440
23440 is a composite number with 20 divisors. Its prime factorisation is × 5 × 293. Divisors (20): 1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 293, 586, 1172, 1465, 2344, 2930 … 23440.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
23440 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
23440 is composite. Its prime factorisation is
- 3
The divisors add up to 54684; without 23440 itself that is 31244, so 23440 is abundant (31244 is more than 23440). Euler's totient φ(23440) = 9344 numbers up to 23440 share no factor with it.
- 4
The digits of 23440 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 38 steps to reach 1.
LaTeX source of the formulas on this page
\[ 23440 = 2^{4} \times 5 \times 293 \]23440 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 20 |
| Sum of divisors | 54684 |
| Euler totient φ(n) | 9344 |
| Square | 549433600 |
| Cube | 12878723584000 |
| Square root | 153.101274 (= 4√1465) |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 38 |
| Scientific notation | 2.344 × |
23440 in other forms
| Form | Value |
|---|---|
| In words | twenty-three thousand four hundred and forty |
| Binary (base 2) | 101101110010000 |
| Octal (base 8) | 55620 |
| Hexadecimal (base 16) | 5B90 |
| Base 3 | 1012011011 |
| As time | 23440 seconds = 6 h 30 min 40 s |
Is 23440 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (23440 ÷ 2 = 11720) | 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 | Yes (23440 ÷ 4 = 5860) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (23440 ÷ 5 = 4688) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 | Yes (23440 ÷ 8 = 2930) | 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 | Yes (23440 ÷ 10 = 2344) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 23440 a prime number?
No. 23440 = × 5 × 293, so it is divisible by 2.
What are the factors of 23440?
1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 293, 586, 1172, 1465, 2344, 2930, 4688, 5860, 11720, 23440.
What is 23440 in binary?
101101110010000 (hexadecimal 5B90, octal 55620).
What is the square root of 23440?
About 153.1013, exactly 4√1465.
Is 23440 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 23440?
It is a composite number with 20 divisors.