The number 2761
2761 is a composite number with 4 divisors. Its prime factorisation is 11 × 251. Divisors (4): 1, 11, 251, 2761.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 2761: a semiprime: 11 × 251, the product of two primes.
- 2
2761 is composite. Its prime factorisation is
- 3
The divisors add up to 3024; without 2761 itself that is 263, so 2761 is deficient (263 is less than 2761). Euler's totient φ(2761) = 2500 numbers up to 2761 share no factor with it.
- 4
The digits of 2761 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 128 steps to reach 1.
LaTeX source of the formulas on this page
\[ 2761 = 11 \times 251 \]
2761 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 3024 |
| Euler totient φ(n) | 2500 |
| Square | 7623121 |
| Cube | 21047437081 |
| Square root | 52.545219 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 128 |
| Scientific notation | 2.761 × |
2761 in other forms
| Form | Value |
|---|---|
| In words | two thousand seven hundred and sixty-one |
| Roman numerals | MMDCCLXI |
| Binary (base 2) | 101011001001 |
| Octal (base 8) | 5311 |
| Hexadecimal (base 16) | AC9 |
| Base 3 | 10210021 |
| As time | 2761 seconds = 46 min 1 s |
Is 2761 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 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | 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 | Yes (2761 ÷ 11 = 251) | 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 2761 a prime number?
No. 2761 = 11 × 251, so it is divisible by 11.
What are the factors of 2761?
1, 11, 251, 2761.
What is 2761 in binary?
101011001001 (hexadecimal AC9, octal 5311).
What is the square root of 2761?
About 52.5452.
What is 2761 in Roman numerals?
MMDCCLXI.
Is 2761 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 2761?
2761 is a semiprime: 11 × 251, the product of two primes.