The number 881
881 is a twin prime (881 and 883 are both prime) and the 152nd prime number. Its only divisors are 1 and 881.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 881: a twin prime (881 and 883 are both prime); the 152nd prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
881 is prime, so its only factors are 1 and 881. It is the 152nd prime; the next prime is 883 and the one before is 877.
- 3
The divisors add up to 882; without 881 itself that is 1, so 881 is deficient (1 is less than 881). Euler's totient φ(881) = 880 numbers up to 881 share no factor with it.
- 4
The digits of 881 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 116 steps to reach 1.
881 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 882 |
| Euler totient φ(n) | 880 |
| Square | 776161 |
| Cube | 683797841 |
| Square root | 29.681644 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 116 |
| Scientific notation | 8.81 × |
881 in other forms
| Form | Value |
|---|---|
| In words | eight hundred and eighty-one |
| Roman numerals | DCCCLXXXI |
| Binary (base 2) | 1101110001 |
| Octal (base 8) | 1561 |
| Hexadecimal (base 16) | 371 |
| Base 3 | 1012122 |
| As time | 881 seconds = 14 min 41 s |
Is 881 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 6) | 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 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 1) | 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 881 a prime number?
Yes. 881 is divisible only by 1 and itself.
What are the factors of 881?
1, 881.
What is 881 in binary?
1101110001 (hexadecimal 371, octal 1561).
What is the square root of 881?
About 29.6816.
What is 881 in Roman numerals?
DCCCLXXXI.
Is 881 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 881?
881 is a twin prime (881 and 883 are both prime); the 152nd prime number; a happy number: repeatedly adding the squares of its digits reaches 1.