The number 43491
43491 is a composite number with 16 divisors. Its prime factorisation is 3 × 7 × 19 × 109. Divisors (16): 1, 3, 7, 19, 21, 57, 109, 133, 327, 399, 763, 2071, 2289, 6213, 14497, 43491.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 43491: a Harshad number: divisible by its digit sum 21.
- 2
43491 is composite. Its prime factorisation is
- 3
The divisors add up to 70400; without 43491 itself that is 26909, so 43491 is deficient (26909 is less than 43491). Euler's totient φ(43491) = 23328 numbers up to 43491 share no factor with it.
- 4
The digits of 43491 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 70 steps to reach 1.
LaTeX source of the formulas on this page
\[ 43491 = 3 \times 7 \times 19 \times 109 \]
43491 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 70400 |
| Euler totient φ(n) | 23328 |
| Square | 1891467081 |
| Cube | 82261794819771 |
| Square root | 208.544959 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 70 |
| Scientific notation | 4.3491 × |
43491 in other forms
| Form | Value |
|---|---|
| In words | forty-three thousand four hundred and ninety-one |
| Binary (base 2) | 1010100111100011 |
| Octal (base 8) | 124743 |
| Hexadecimal (base 16) | A9E3 |
| Base 3 | 2012122210 |
| As time | 43491 seconds = 12 h 4 min 51 s |
Is 43491 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 (43491 ÷ 3 = 14497) | 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 1) | 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 | Yes (43491 ÷ 7 = 6213) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | 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 43491 a prime number?
No. 43491 = 3 × 7 × 19 × 109, so it is divisible by 3.
What are the factors of 43491?
1, 3, 7, 19, 21, 57, 109, 133, 327, 399, 763, 2071, 2289, 6213, 14497, 43491.
What is 43491 in binary?
1010100111100011 (hexadecimal A9E3, octal 124743).
What is the square root of 43491?
About 208.5450.
Is 43491 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 43491?
43491 is a Harshad number: divisible by its digit sum 21.