The number 41981
41981 is a twin prime (41981 and 41983 are both prime) and the 4390th prime number. Its only divisors are 1 and 41981.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 41981: a twin prime (41981 and 41983 are both prime); the 4390th prime number.
- 2
41981 is prime, so its only factors are 1 and 41981. It is the 4390th prime; the next prime is 41983 and the one before is 41969.
- 3
The divisors add up to 41982; without 41981 itself that is 1, so 41981 is deficient (1 is less than 41981). Euler's totient φ(41981) = 41980 numbers up to 41981 share no factor with it.
- 4
The digits of 41981 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 88 steps to reach 1.
41981 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 41982 |
| Euler totient φ(n) | 41980 |
| Square | 1762404361 |
| Cube | 73987497479141 |
| Square root | 204.892655 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 88 |
| Scientific notation | 4.1981 × |
41981 in other forms
| Form | Value |
|---|---|
| In words | forty-one thousand nine hundred and eighty-one |
| Binary (base 2) | 1010001111111101 |
| Octal (base 8) | 121775 |
| Hexadecimal (base 16) | A3FD |
| Base 3 | 2010120212 |
| As time | 41981 seconds = 11 h 39 min 41 s |
Is 41981 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 1) | 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 2) | 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 5) | 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 41981 a prime number?
Yes. 41981 is divisible only by 1 and itself.
What are the factors of 41981?
1, 41981.
What is 41981 in binary?
1010001111111101 (hexadecimal A3FD, octal 121775).
What is the square root of 41981?
About 204.8927.
Is 41981 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 41981?
41981 is a twin prime (41981 and 41983 are both prime); the 4390th prime number.