The number 1181
1181 is the 194th prime number. Its only divisors are 1 and 1181.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1181: the 194th prime number.
- 2
1181 is prime, so its only factors are 1 and 1181. It is the 194th prime; the next prime is 1187 and the one before is 1171.
- 3
The divisors add up to 1182; without 1181 itself that is 1, so 1181 is deficient (1 is less than 1181). Euler's totient φ(1181) = 1180 numbers up to 1181 share no factor with it.
- 4
The digits of 1181 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 57 steps to reach 1.
1181 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 1182 |
| Euler totient φ(n) | 1180 |
| Square | 1394761 |
| Cube | 1647212741 |
| Square root | 34.365681 |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 57 |
| Scientific notation | 1.181 × |
1181 in other forms
| Form | Value |
|---|---|
| In words | one thousand one hundred and eighty-one |
| Roman numerals | MCLXXXI |
| Binary (base 2) | 10010011101 |
| Octal (base 8) | 2235 |
| Hexadecimal (base 16) | 49D |
| Base 3 | 1121202 |
| As time | 1181 seconds = 19 min 41 s |
Is 1181 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 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | 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 4) | 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 1181 a prime number?
Yes. 1181 is divisible only by 1 and itself.
What are the factors of 1181?
1, 1181.
What is 1181 in binary?
10010011101 (hexadecimal 49D, octal 2235).
What is the square root of 1181?
About 34.3657.
What is 1181 in Roman numerals?
MCLXXXI.
Is 1181 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 1181?
1181 is the 194th prime number.