The number 8440
8440 is a composite number with 16 divisors. Its prime factorisation is × 5 × 211. Divisors (16): 1, 2, 4, 5, 8, 10, 20, 40, 211, 422, 844, 1055, 1688, 2110, 4220, 8440.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
8440 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
8440 is composite. Its prime factorisation is
- 3
The divisors add up to 19080; without 8440 itself that is 10640, so 8440 is abundant (10640 is more than 8440). Euler's totient φ(8440) = 3360 numbers up to 8440 share no factor with it.
- 4
The digits of 8440 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 171 steps to reach 1.
LaTeX source of the formulas on this page
\[ 8440 = 2^{3} \times 5 \times 211 \]8440 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 19080 |
| Euler totient φ(n) | 3360 |
| Square | 71233600 |
| Cube | 601211584000 |
| Square root | 91.869473 (= 2√2110) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 171 |
| Scientific notation | 8.44 × |
8440 in other forms
| Form | Value |
|---|---|
| In words | eight thousand four hundred and forty |
| Binary (base 2) | 10000011111000 |
| Octal (base 8) | 20370 |
| Hexadecimal (base 16) | 20F8 |
| Base 3 | 102120121 |
| As time | 8440 seconds = 2 h 20 min 40 s |
Is 8440 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (8440 ÷ 2 = 4220) | 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 (8440 ÷ 4 = 2110) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (8440 ÷ 5 = 1688) | 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 5) | 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 (8440 ÷ 8 = 1055) | 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 (8440 ÷ 10 = 844) | 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 8440 a prime number?
No. 8440 = × 5 × 211, so it is divisible by 2.
What are the factors of 8440?
1, 2, 4, 5, 8, 10, 20, 40, 211, 422, 844, 1055, 1688, 2110, 4220, 8440.
What is 8440 in binary?
10000011111000 (hexadecimal 20F8, octal 20370).
What is the square root of 8440?
About 91.8695, exactly 2√2110.
Is 8440 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 8440?
It is a composite number with 16 divisors.