The number 2931
2931 is a composite number with 4 divisors. Its prime factorisation is 3 × 977. Divisors (4): 1, 3, 977, 2931.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 2931: a semiprime: 3 × 977, the product of two primes.
- 2
2931 is composite. Its prime factorisation is
- 3
The divisors add up to 3912; without 2931 itself that is 981, so 2931 is deficient (981 is less than 2931). Euler's totient φ(2931) = 1952 numbers up to 2931 share no factor with it.
- 4
The digits of 2931 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 35 steps to reach 1.
LaTeX source of the formulas on this page
\[ 2931 = 3 \times 977 \]
2931 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 3912 |
| Euler totient φ(n) | 1952 |
| Square | 8590761 |
| Cube | 25179520491 |
| Square root | 54.138711 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 35 |
| Scientific notation | 2.931 × |
2931 in other forms
| Form | Value |
|---|---|
| In words | two thousand nine hundred and thirty-one |
| Roman numerals | MMCMXXXI |
| Binary (base 2) | 101101110011 |
| Octal (base 8) | 5563 |
| Hexadecimal (base 16) | B73 |
| Base 3 | 11000120 |
| As time | 2931 seconds = 48 min 51 s |
Is 2931 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 (2931 ÷ 3 = 977) | 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 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | 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 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 2931 a prime number?
No. 2931 = 3 × 977, so it is divisible by 3.
What are the factors of 2931?
1, 3, 977, 2931.
What is 2931 in binary?
101101110011 (hexadecimal B73, octal 5563).
What is the square root of 2931?
About 54.1387.
What is 2931 in Roman numerals?
MMCMXXXI.
Is 2931 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 2931?
2931 is a semiprime: 3 × 977, the product of two primes.