The number 79440
79440 is a composite number with 40 divisors. Its prime factorisation is × 3 × 5 × 331. Divisors (40): 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 40, 48 … 79440.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 79440: a Harshad number: divisible by its digit sum 24.
- 2
79440 is composite. Its prime factorisation is
- 3
The divisors add up to 247008; without 79440 itself that is 167568, so 79440 is abundant (167568 is more than 79440). Euler's totient φ(79440) = 21120 numbers up to 79440 share no factor with it.
- 4
The digits of 79440 add up to 24, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 45 steps to reach 1.
LaTeX source of the formulas on this page
\[ 79440 = 2^{4} \times 3 \times 5 \times 331 \]79440 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 40 |
| Sum of divisors | 247008 |
| Euler totient φ(n) | 21120 |
| Square | 6310713600 |
| Cube | 501323088384000 |
| Square root | 281.851024 (= 4√4965) |
| Digit sum / digital root | 24 / 6 |
| Collatz steps to 1 | 45 |
| Scientific notation | 7.944 × |
79440 in other forms
| Form | Value |
|---|---|
| In words | seventy-nine thousand four hundred and forty |
| Binary (base 2) | 10011011001010000 |
| Octal (base 8) | 233120 |
| Hexadecimal (base 16) | 13650 |
| Base 3 | 11000222020 |
| As time | 79440 seconds = 22 h 4 min 0 s |
Is 79440 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (79440 ÷ 2 = 39720) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (79440 ÷ 3 = 26480) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (79440 ÷ 4 = 19860) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (79440 ÷ 5 = 15888) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (79440 ÷ 6 = 13240) | 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 | Yes (79440 ÷ 8 = 9930) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (79440 ÷ 10 = 7944) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (79440 ÷ 12 = 6620) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 79440 a prime number?
No. 79440 = × 3 × 5 × 331, so it is divisible by 2.
What are the factors of 79440?
1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 40, 48, 60, 80, 120, 240, 331, 662, 993, 1324, 1655, 1986, 2648, 3310, 3972, 4965, 5296, 6620, 7944, 9930, 13240, 15888, 19860, 26480, 39720, 79440.
What is 79440 in binary?
10011011001010000 (hexadecimal 13650, octal 233120).
What is the square root of 79440?
About 281.8510, exactly 4√4965.
Is 79440 divisible by 3?
Yes. Its digits add up to 24, a multiple of 3.
What is special about the number 79440?
79440 is a Harshad number: divisible by its digit sum 24.