The number 39440
39440 is a composite number with 40 divisors. Its prime factorisation is × 5 × 17 × 29. Divisors (40): 1, 2, 4, 5, 8, 10, 16, 17, 20, 29, 34, 40, 58, 68, 80, 85 … 39440.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 39440: a Harshad number: divisible by its digit sum 20.
- 2
39440 is composite. Its prime factorisation is
- 3
The divisors add up to 100440; without 39440 itself that is 61000, so 39440 is abundant (61000 is more than 39440). Euler's totient φ(39440) = 14336 numbers up to 39440 share no factor with it.
- 4
The digits of 39440 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 75 steps to reach 1.
LaTeX source of the formulas on this page
\[ 39440 = 2^{4} \times 5 \times 17 \times 29 \]39440 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 40 |
| Sum of divisors | 100440 |
| Euler totient φ(n) | 14336 |
| Square | 1555513600 |
| Cube | 61349456384000 |
| Square root | 198.595065 (= 4√2465) |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 75 |
| Scientific notation | 3.944 × |
39440 in other forms
| Form | Value |
|---|---|
| In words | thirty-nine thousand four hundred and forty |
| Binary (base 2) | 1001101000010000 |
| Octal (base 8) | 115020 |
| Hexadecimal (base 16) | 9A10 |
| Base 3 | 2000002202 |
| As time | 39440 seconds = 10 h 57 min 20 s |
Is 39440 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (39440 ÷ 2 = 19720) | 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 | Yes (39440 ÷ 4 = 9860) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (39440 ÷ 5 = 7888) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | 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 (39440 ÷ 8 = 4930) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (39440 ÷ 10 = 3944) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 39440 a prime number?
No. 39440 = × 5 × 17 × 29, so it is divisible by 2.
What are the factors of 39440?
1, 2, 4, 5, 8, 10, 16, 17, 20, 29, 34, 40, 58, 68, 80, 85, 116, 136, 145, 170, 232, 272, 290, 340, 464, 493, 580, 680, 986, 1160, 1360, 1972, 2320, 2465, 3944, 4930, 7888, 9860, 19720, 39440.
What is 39440 in binary?
1001101000010000 (hexadecimal 9A10, octal 115020).
What is the square root of 39440?
About 198.5951, exactly 4√2465.
Is 39440 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 39440?
39440 is a Harshad number: divisible by its digit sum 20.