The number 1151
1151 is a twin prime (1151 and 1153 are both prime) and the 190th prime number. Its only divisors are 1 and 1151.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1151: a twin prime (1151 and 1153 are both prime); the 190th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
1151 is prime, so its only factors are 1 and 1151. It is the 190th prime; the next prime is 1153 and the one before is 1129.
- 3
The divisors add up to 1152; without 1151 itself that is 1, so 1151 is deficient (1 is less than 1151). Euler's totient φ(1151) = 1150 numbers up to 1151 share no factor with it.
- 4
The digits of 1151 add up to 8, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 57 steps to reach 1.
1151 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 1152 |
| Euler totient φ(n) | 1150 |
| Square | 1324801 |
| Cube | 1524845951 |
| Square root | 33.926391 |
| Digit sum / digital root | 8 / 8 |
| Collatz steps to 1 | 57 |
| Scientific notation | 1.151 × |
1151 in other forms
| Form | Value |
|---|---|
| In words | one thousand one hundred and fifty-one |
| Roman numerals | MCLI |
| Binary (base 2) | 10001111111 |
| Octal (base 8) | 2177 |
| Hexadecimal (base 16) | 47F |
| Base 3 | 1120122 |
| As time | 1151 seconds = 19 min 11 s |
Is 1151 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 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 5) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | 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 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1151 a prime number?
Yes. 1151 is divisible only by 1 and itself.
What are the factors of 1151?
1, 1151.
What is 1151 in binary?
10001111111 (hexadecimal 47F, octal 2177).
What is the square root of 1151?
About 33.9264.
What is 1151 in Roman numerals?
MCLI.
Is 1151 divisible by 3?
No. Its digits add up to 8, which is not a multiple of 3.
What is special about the number 1151?
1151 is a twin prime (1151 and 1153 are both prime); the 190th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.