The number 40991
40991 is a composite number with 4 divisors. Its prime factorisation is 179 × 229. Divisors (4): 1, 179, 229, 40991.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 40991: a semiprime: 179 × 229, the product of two primes.
- 2
40991 is composite. Its prime factorisation is
- 3
The divisors add up to 41400; without 40991 itself that is 409, so 40991 is deficient (409 is less than 40991). Euler's totient φ(40991) = 40584 numbers up to 40991 share no factor with it.
- 4
The digits of 40991 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 168 steps to reach 1.
LaTeX source of the formulas on this page
\[ 40991 = 179 \times 229 \]
40991 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 41400 |
| Euler totient φ(n) | 40584 |
| Square | 1680262081 |
| Cube | 68875622962271 |
| Square root | 202.462342 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 168 |
| Scientific notation | 4.0991 × |
40991 in other forms
| Form | Value |
|---|---|
| In words | forty thousand nine hundred and ninety-one |
| Binary (base 2) | 1010000000011111 |
| Octal (base 8) | 120037 |
| Hexadecimal (base 16) | A01F |
| Base 3 | 2002020012 |
| As time | 40991 seconds = 11 h 23 min 11 s |
Is 40991 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 2) | 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 5) | 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 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 40991 a prime number?
No. 40991 = 179 × 229, so it is divisible by 179.
What are the factors of 40991?
1, 179, 229, 40991.
What is 40991 in binary?
1010000000011111 (hexadecimal A01F, octal 120037).
What is the square root of 40991?
About 202.4623.
Is 40991 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 40991?
40991 is a semiprime: 179 × 229, the product of two primes.