The number 2961
2961 is a composite number with 12 divisors. Its prime factorisation is × 7 × 47. Divisors (12): 1, 3, 7, 9, 21, 47, 63, 141, 329, 423, 987, 2961.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
2961 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
2961 is composite. Its prime factorisation is
- 3
The divisors add up to 4992; without 2961 itself that is 2031, so 2961 is deficient (2031 is less than 2961). Euler's totient φ(2961) = 1656 numbers up to 2961 share no factor with it.
- 4
The digits of 2961 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 35 steps to reach 1.
LaTeX source of the formulas on this page
\[ 2961 = 3^{2} \times 7 \times 47 \]2961 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 4992 |
| Euler totient φ(n) | 1656 |
| Square | 8767521 |
| Cube | 25960629681 |
| Square root | 54.415071 (= 3√329) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 35 |
| Scientific notation | 2.961 × |
2961 in other forms
| Form | Value |
|---|---|
| In words | two thousand nine hundred and sixty-one |
| Roman numerals | MMCMLXI |
| Binary (base 2) | 101110010001 |
| Octal (base 8) | 5621 |
| Hexadecimal (base 16) | B91 |
| Base 3 | 11001200 |
| As time | 2961 seconds = 49 min 21 s |
Is 2961 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 (2961 ÷ 3 = 987) | 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 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (2961 ÷ 7 = 423) | 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 | Yes (2961 ÷ 9 = 329) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 2961 a prime number?
No. 2961 = × 7 × 47, so it is divisible by 3.
What are the factors of 2961?
1, 3, 7, 9, 21, 47, 63, 141, 329, 423, 987, 2961.
What is 2961 in binary?
101110010001 (hexadecimal B91, octal 5621).
What is the square root of 2961?
About 54.4151, exactly 3√329.
What is 2961 in Roman numerals?
MMCMLXI.
Is 2961 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 2961?
It is a composite number with 12 divisors.