The number 1085
1085 is a composite number with 8 divisors. Its prime factorisation is 5 × 7 × 31. Divisors (8): 1, 5, 7, 31, 35, 155, 217, 1085.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
1085 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
1085 is composite. Its prime factorisation is
- 3
The divisors add up to 1536; without 1085 itself that is 451, so 1085 is deficient (451 is less than 1085). Euler's totient φ(1085) = 720 numbers up to 1085 share no factor with it.
- 4
The digits of 1085 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 44 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1085 = 5 \times 7 \times 31 \]
1085 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 1536 |
| Euler totient φ(n) | 720 |
| Square | 1177225 |
| Cube | 1277289125 |
| Square root | 32.939338 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 44 |
| Scientific notation | 1.085 × |
1085 in other forms
| Form | Value |
|---|---|
| In words | one thousand and eighty-five |
| Roman numerals | MLXXXV |
| Binary (base 2) | 10000111101 |
| Octal (base 8) | 2075 |
| Hexadecimal (base 16) | 43D |
| Base 3 | 1111012 |
| As time | 1085 seconds = 18 min 5 s |
Is 1085 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 | Yes (1085 ÷ 5 = 217) | 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 | Yes (1085 ÷ 7 = 155) | 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 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1085 a prime number?
No. 1085 = 5 × 7 × 31, so it is divisible by 5.
What are the factors of 1085?
1, 5, 7, 31, 35, 155, 217, 1085.
What is 1085 in binary?
10000111101 (hexadecimal 43D, octal 2075).
What is the square root of 1085?
About 32.9393.
What is 1085 in Roman numerals?
MLXXXV.
Is 1085 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 1085?
It is a composite number with 8 divisors.