The number 856
856 is a composite number with 8 divisors. Its prime factorisation is × 107. Divisors (8): 1, 2, 4, 8, 107, 214, 428, 856.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
856 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
856 is composite. Its prime factorisation is
- 3
The divisors add up to 1620; without 856 itself that is 764, so 856 is deficient (764 is less than 856). Euler's totient φ(856) = 424 numbers up to 856 share no factor with it.
- 4
The digits of 856 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 103 steps to reach 1.
LaTeX source of the formulas on this page
\[ 856 = 2^{3} \times 107 \]856 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 1620 |
| Euler totient φ(n) | 424 |
| Square | 732736 |
| Cube | 627222016 |
| Square root | 29.257478 (= 2√214) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 103 |
| Scientific notation | 8.56 × |
856 in other forms
| Form | Value |
|---|---|
| In words | eight hundred and fifty-six |
| Roman numerals | DCCCLVI |
| Binary (base 2) | 1101011000 |
| Octal (base 8) | 1530 |
| Hexadecimal (base 16) | 358 |
| Base 3 | 1011201 |
| As time | 856 seconds = 14 min 16 s |
Is 856 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (856 ÷ 2 = 428) | 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 | Yes (856 ÷ 4 = 214) | 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 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 | Yes (856 ÷ 8 = 107) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 6) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 856 a prime number?
No. 856 = × 107, so it is divisible by 2.
What are the factors of 856?
1, 2, 4, 8, 107, 214, 428, 856.
What is 856 in binary?
1101011000 (hexadecimal 358, octal 1530).
What is the square root of 856?
About 29.2575, exactly 2√214.
What is 856 in Roman numerals?
DCCCLVI.
Is 856 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 856?
It is a composite number with 8 divisors.