The number 78009
78009 is a composite number with 4 divisors. Its prime factorisation is 3 × 26003. Divisors (4): 1, 3, 26003, 78009.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 78009: a semiprime: 3 × 26003, the product of two primes.
- 2
78009 is composite. Its prime factorisation is
- 3
The divisors add up to 104016; without 78009 itself that is 26007, so 78009 is deficient (26007 is less than 78009). Euler's totient φ(78009) = 52004 numbers up to 78009 share no factor with it.
- 4
The digits of 78009 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 169 steps to reach 1.
LaTeX source of the formulas on this page
\[ 78009 = 3 \times 26003 \]
78009 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 104016 |
| Euler totient φ(n) | 52004 |
| Square | 6085404081 |
| Cube | 474716286954729 |
| Square root | 279.300913 |
| Digit sum / digital root | 24 / 6 |
| Collatz steps to 1 | 169 |
| Scientific notation | 7.8009 × |
78009 in other forms
| Form | Value |
|---|---|
| In words | seventy-eight thousand and nine |
| Binary (base 2) | 10011000010111001 |
| Octal (base 8) | 230271 |
| Hexadecimal (base 16) | 130B9 |
| Base 3 | 10222000020 |
| As time | 78009 seconds = 21 h 40 min 9 s |
Is 78009 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (78009 ÷ 3 = 26003) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 1) | 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 | No (remainder 9) | 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 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 78009 a prime number?
No. 78009 = 3 × 26003, so it is divisible by 3.
What are the factors of 78009?
1, 3, 26003, 78009.
What is 78009 in binary?
10011000010111001 (hexadecimal 130B9, octal 230271).
What is the square root of 78009?
About 279.3009.
Is 78009 divisible by 3?
Yes. Its digits add up to 24, a multiple of 3.
What is special about the number 78009?
78009 is a semiprime: 3 × 26003, the product of two primes.