The number 1385
1385 is a composite number with 4 divisors. Its prime factorisation is 5 × 277. Divisors (4): 1, 5, 277, 1385.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1385: a semiprime: 5 × 277, the product of two primes.
- 2
1385 is composite. Its prime factorisation is
- 3
The divisors add up to 1668; without 1385 itself that is 283, so 1385 is deficient (283 is less than 1385). Euler's totient φ(1385) = 1104 numbers up to 1385 share no factor with it.
- 4
The digits of 1385 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 65 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1385 = 5 \times 277 \]
1385 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 1668 |
| Euler totient φ(n) | 1104 |
| Square | 1918225 |
| Cube | 2656741625 |
| Square root | 37.215588 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 65 |
| Scientific notation | 1.385 × |
1385 in other forms
| Form | Value |
|---|---|
| In words | one thousand three hundred and eighty-five |
| Roman numerals | MCCCLXXXV |
| Binary (base 2) | 10101101001 |
| Octal (base 8) | 2551 |
| Hexadecimal (base 16) | 569 |
| Base 3 | 1220022 |
| As time | 1385 seconds = 23 min 5 s |
Is 1385 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 (1385 ÷ 5 = 277) | 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 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | 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 1385 a prime number?
No. 1385 = 5 × 277, so it is divisible by 5.
What are the factors of 1385?
1, 5, 277, 1385.
What is 1385 in binary?
10101101001 (hexadecimal 569, octal 2551).
What is the square root of 1385?
About 37.2156.
What is 1385 in Roman numerals?
MCCCLXXXV.
Is 1385 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 1385?
1385 is a semiprime: 5 × 277, the product of two primes.