The number 40840
40840 is a composite number with 16 divisors. Its prime factorisation is × 5 × 1021. Divisors (16): 1, 2, 4, 5, 8, 10, 20, 40, 1021, 2042, 4084, 5105, 8168, 10210, 20420, 40840.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
40840 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
40840 is composite. Its prime factorisation is
- 3
The divisors add up to 91980; without 40840 itself that is 51140, so 40840 is abundant (51140 is more than 40840). Euler's totient φ(40840) = 16320 numbers up to 40840 share no factor with it.
- 4
The digits of 40840 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 62 steps to reach 1.
LaTeX source of the formulas on this page
\[ 40840 = 2^{3} \times 5 \times 1021 \]40840 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 91980 |
| Euler totient φ(n) | 16320 |
| Square | 1667905600 |
| Cube | 68117264704000 |
| Square root | 202.089089 (= 2√10210) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 62 |
| Scientific notation | 4.084 × |
40840 in other forms
| Form | Value |
|---|---|
| In words | forty thousand eight hundred and forty |
| Binary (base 2) | 1001111110001000 |
| Octal (base 8) | 117610 |
| Hexadecimal (base 16) | 9F88 |
| Base 3 | 2002000121 |
| As time | 40840 seconds = 11 h 20 min 40 s |
Is 40840 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (40840 ÷ 2 = 20420) | 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 (40840 ÷ 4 = 10210) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (40840 ÷ 5 = 8168) | 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 2) | 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 (40840 ÷ 8 = 5105) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (40840 ÷ 10 = 4084) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | 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 40840 a prime number?
No. 40840 = × 5 × 1021, so it is divisible by 2.
What are the factors of 40840?
1, 2, 4, 5, 8, 10, 20, 40, 1021, 2042, 4084, 5105, 8168, 10210, 20420, 40840.
What is 40840 in binary?
1001111110001000 (hexadecimal 9F88, octal 117610).
What is the square root of 40840?
About 202.0891, exactly 2√10210.
Is 40840 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 40840?
It is a composite number with 16 divisors.