The number 1841
1841 is a composite number with 4 divisors. Its prime factorisation is 7 × 263. Divisors (4): 1, 7, 263, 1841.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1841: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 7 × 263, the product of two primes.
- 2
1841 is composite. Its prime factorisation is
- 3
The divisors add up to 2112; without 1841 itself that is 271, so 1841 is deficient (271 is less than 1841). Euler's totient φ(1841) = 1572 numbers up to 1841 share no factor with it.
- 4
The digits of 1841 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 130 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1841 = 7 \times 263 \]
1841 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 2112 |
| Euler totient φ(n) | 1572 |
| Square | 3389281 |
| Cube | 6239666321 |
| Square root | 42.906876 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 130 |
| Scientific notation | 1.841 × |
1841 in other forms
| Form | Value |
|---|---|
| In words | one thousand eight hundred and forty-one |
| Roman numerals | MDCCCXLI |
| Binary (base 2) | 11100110001 |
| Octal (base 8) | 3461 |
| Hexadecimal (base 16) | 731 |
| Base 3 | 2112012 |
| As time | 1841 seconds = 30 min 41 s |
Is 1841 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 | Yes (1841 ÷ 7 = 263) | 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 5) | 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 4) | 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 1841 a prime number?
No. 1841 = 7 × 263, so it is divisible by 7.
What are the factors of 1841?
1, 7, 263, 1841.
What is 1841 in binary?
11100110001 (hexadecimal 731, octal 3461).
What is the square root of 1841?
About 42.9069.
What is 1841 in Roman numerals?
MDCCCXLI.
Is 1841 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 1841?
1841 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 7 × 263, the product of two primes.