The number 23840
23840 is a composite number with 24 divisors. Its prime factorisation is × 5 × 149. Divisors (24): 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 80, 149, 160, 298, 596, 745 … 23840.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
23840 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
23840 is composite. Its prime factorisation is
- 3
The divisors add up to 56700; without 23840 itself that is 32860, so 23840 is abundant (32860 is more than 23840). Euler's totient φ(23840) = 9472 numbers up to 23840 share no factor with it.
- 4
The digits of 23840 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 95 steps to reach 1.
LaTeX source of the formulas on this page
\[ 23840 = 2^{5} \times 5 \times 149 \]23840 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 56700 |
| Euler totient φ(n) | 9472 |
| Square | 568345600 |
| Cube | 13549359104000 |
| Square root | 154.402073 (= 4√1490) |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 95 |
| Scientific notation | 2.384 × |
23840 in other forms
| Form | Value |
|---|---|
| In words | twenty-three thousand eight hundred and forty |
| Binary (base 2) | 101110100100000 |
| Octal (base 8) | 56440 |
| Hexadecimal (base 16) | 5D20 |
| Base 3 | 1012200222 |
| As time | 23840 seconds = 6 h 37 min 20 s |
Is 23840 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (23840 ÷ 2 = 11920) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (23840 ÷ 4 = 5960) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (23840 ÷ 5 = 4768) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 (23840 ÷ 8 = 2980) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (23840 ÷ 10 = 2384) | 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 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 23840 a prime number?
No. 23840 = × 5 × 149, so it is divisible by 2.
What are the factors of 23840?
1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 80, 149, 160, 298, 596, 745, 1192, 1490, 2384, 2980, 4768, 5960, 11920, 23840.
What is 23840 in binary?
101110100100000 (hexadecimal 5D20, octal 56440).
What is the square root of 23840?
About 154.4021, exactly 4√1490.
Is 23840 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 23840?
It is a composite number with 24 divisors.