The number 40842
40842 is a composite number with 12 divisors. Its prime factorisation is 2 × × 2269. Divisors (12): 1, 2, 3, 6, 9, 18, 2269, 4538, 6807, 13614, 20421, 40842.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 40842: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.
- 2
40842 is composite. Its prime factorisation is
- 3
The divisors add up to 88530; without 40842 itself that is 47688, so 40842 is abundant (47688 is more than 40842). Euler's totient φ(40842) = 13608 numbers up to 40842 share no factor with it.
- 4
The digits of 40842 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 62 steps to reach 1.
LaTeX source of the formulas on this page
\[ 40842 = 2 \times 3^{2} \times 2269 \]40842 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 88530 |
| Euler totient φ(n) | 13608 |
| Square | 1668068964 |
| Cube | 68127272627688 |
| Square root | 202.094038 (= 3√4538) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 62 |
| Scientific notation | 4.0842 × |
40842 in other forms
| Form | Value |
|---|---|
| In words | forty thousand eight hundred and forty-two |
| Binary (base 2) | 1001111110001010 |
| Octal (base 8) | 117612 |
| Hexadecimal (base 16) | 9F8A |
| Base 3 | 2002000200 |
| As time | 40842 seconds = 11 h 20 min 42 s |
Is 40842 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (40842 ÷ 2 = 20421) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (40842 ÷ 3 = 13614) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (40842 ÷ 6 = 6807) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (40842 ÷ 9 = 4538) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 2) | 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 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 40842 a prime number?
No. 40842 = 2 × × 2269, so it is divisible by 2.
What are the factors of 40842?
1, 2, 3, 6, 9, 18, 2269, 4538, 6807, 13614, 20421, 40842.
What is 40842 in binary?
1001111110001010 (hexadecimal 9F8A, octal 117612).
What is the square root of 40842?
About 202.0940, exactly 3√4538.
Is 40842 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 40842?
40842 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.