The number 67840
67840 is a composite number with 36 divisors. Its prime factorisation is × 5 × 53. Divisors (36): 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 53, 64, 80, 106, 128, 160 … 67840.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
67840 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
67840 is composite. Its prime factorisation is
- 3
The divisors add up to 165564; without 67840 itself that is 97724, so 67840 is abundant (97724 is more than 67840). Euler's totient φ(67840) = 26624 numbers up to 67840 share no factor with it.
- 4
The digits of 67840 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 130 steps to reach 1.
LaTeX source of the formulas on this page
\[ 67840 = 2^{8} \times 5 \times 53 \]67840 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 36 |
| Sum of divisors | 165564 |
| Euler totient φ(n) | 26624 |
| Square | 4602265600 |
| Cube | 312217698304000 |
| Square root | 260.461130 (= 16√265) |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 130 |
| Scientific notation | 6.784 × |
67840 in other forms
| Form | Value |
|---|---|
| In words | sixty-seven thousand eight hundred and forty |
| Binary (base 2) | 10000100100000000 |
| Octal (base 8) | 204400 |
| Hexadecimal (base 16) | 10900 |
| Base 3 | 10110001121 |
| As time | 67840 seconds = 18 h 50 min 40 s |
Is 67840 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (67840 ÷ 2 = 33920) | 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 (67840 ÷ 4 = 16960) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (67840 ÷ 5 = 13568) | 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 3) | 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 (67840 ÷ 8 = 8480) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (67840 ÷ 10 = 6784) | 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 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 67840 a prime number?
No. 67840 = × 5 × 53, so it is divisible by 2.
What are the factors of 67840?
1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 53, 64, 80, 106, 128, 160, 212, 256, 265, 320, 424, 530, 640, 848, 1060, 1280, 1696, 2120, 3392, 4240, 6784, 8480, 13568, 16960, 33920, 67840.
What is 67840 in binary?
10000100100000000 (hexadecimal 10900, octal 204400).
What is the square root of 67840?
About 260.4611, exactly 16√265.
Is 67840 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 67840?
It is a composite number with 36 divisors.