The number 12961
12961 is a composite number with 4 divisors. Its prime factorisation is 13 × 997. Divisors (4): 1, 13, 997, 12961.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 12961: a semiprime: 13 × 997, the product of two primes.
- 2
12961 is composite. Its prime factorisation is
- 3
The divisors add up to 13972; without 12961 itself that is 1011, so 12961 is deficient (1011 is less than 12961). Euler's totient φ(12961) = 11952 numbers up to 12961 share no factor with it.
- 4
The digits of 12961 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 169 steps to reach 1.
LaTeX source of the formulas on this page
\[ 12961 = 13 \times 997 \]
12961 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 13972 |
| Euler totient φ(n) | 11952 |
| Square | 167987521 |
| Cube | 2177286259681 |
| Square root | 113.846388 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 169 |
| Scientific notation | 1.2961 × |
12961 in other forms
| Form | Value |
|---|---|
| In words | twelve thousand nine hundred and sixty-one |
| Binary (base 2) | 11001010100001 |
| Octal (base 8) | 31241 |
| Hexadecimal (base 16) | 32A1 |
| Base 3 | 122210001 |
| As time | 12961 seconds = 3 h 36 min 1 s |
Is 12961 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 1) | 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | 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 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 12961 a prime number?
No. 12961 = 13 × 997, so it is divisible by 13.
What are the factors of 12961?
1, 13, 997, 12961.
What is 12961 in binary?
11001010100001 (hexadecimal 32A1, octal 31241).
What is the square root of 12961?
About 113.8464.
Is 12961 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 12961?
12961 is a semiprime: 13 × 997, the product of two primes.