The number 5981
5981 is the 782nd prime number and a binary palindrome (1011101011101). Its only divisors are 1 and 5981.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 5981: the 782nd prime number; a binary palindrome (1011101011101).
- 2
5981 is prime, so its only factors are 1 and 5981. It is the 782nd prime; the next prime is 5987 and the one before is 5953.
- 3
The divisors add up to 5982; without 5981 itself that is 1, so 5981 is deficient (1 is less than 5981). Euler's totient φ(5981) = 5980 numbers up to 5981 share no factor with it.
- 4
The digits of 5981 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 49 steps to reach 1.
5981 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 5982 |
| Euler totient φ(n) | 5980 |
| Square | 35772361 |
| Cube | 213954491141 |
| Square root | 77.336925 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 49 |
| Scientific notation | 5.981 × |
5981 in other forms
| Form | Value |
|---|---|
| In words | five thousand nine hundred and eighty-one |
| Binary (base 2) | 1011101011101 |
| Octal (base 8) | 13535 |
| Hexadecimal (base 16) | 175D |
| Base 3 | 22012112 |
| As time | 5981 seconds = 1 h 39 min 41 s |
Is 5981 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 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 | 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 8) | 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 5981 a prime number?
Yes. 5981 is divisible only by 1 and itself.
What are the factors of 5981?
1, 5981.
What is 5981 in binary?
1011101011101 (hexadecimal 175D, octal 13535).
What is the square root of 5981?
About 77.3369.
Is 5981 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 5981?
5981 is the 782nd prime number; a binary palindrome (1011101011101).