The number 1840
1840 is a composite number with 20 divisors. Its prime factorisation is × 5 × 23. Divisors (20): 1, 2, 4, 5, 8, 10, 16, 20, 23, 40, 46, 80, 92, 115, 184, 230 … 1840.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
1840 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
1840 is composite. Its prime factorisation is
- 3
The divisors add up to 4464; without 1840 itself that is 2624, so 1840 is abundant (2624 is more than 1840). Euler's totient φ(1840) = 704 numbers up to 1840 share no factor with it.
- 4
The digits of 1840 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 37 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1840 = 2^{4} \times 5 \times 23 \]1840 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 20 |
| Sum of divisors | 4464 |
| Euler totient φ(n) | 704 |
| Square | 3385600 |
| Cube | 6229504000 |
| Square root | 42.895221 (= 4√115) |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 37 |
| Scientific notation | 1.84 × |
1840 in other forms
| Form | Value |
|---|---|
| In words | one thousand eight hundred and forty |
| Roman numerals | MDCCCXL |
| Binary (base 2) | 11100110000 |
| Octal (base 8) | 3460 |
| Hexadecimal (base 16) | 730 |
| Base 3 | 2112011 |
| As time | 1840 seconds = 30 min 40 s |
Is 1840 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (1840 ÷ 2 = 920) | 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 (1840 ÷ 4 = 460) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (1840 ÷ 5 = 368) | 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 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 | Yes (1840 ÷ 8 = 230) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (1840 ÷ 10 = 184) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | 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 1840 a prime number?
No. 1840 = × 5 × 23, so it is divisible by 2.
What are the factors of 1840?
1, 2, 4, 5, 8, 10, 16, 20, 23, 40, 46, 80, 92, 115, 184, 230, 368, 460, 920, 1840.
What is 1840 in binary?
11100110000 (hexadecimal 730, octal 3460).
What is the square root of 1840?
About 42.8952, exactly 4√115.
What is 1840 in Roman numerals?
MDCCCXL.
Is 1840 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 1840?
It is a composite number with 20 divisors.