The number 77005
77005 is a composite number with 4 divisors. Its prime factorisation is 5 × 15401. Divisors (4): 1, 5, 15401, 77005.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 77005: a semiprime: 5 × 15401, the product of two primes.
- 2
77005 is composite. Its prime factorisation is
- 3
The divisors add up to 92412; without 77005 itself that is 15407, so 77005 is deficient (15407 is less than 77005). Euler's totient φ(77005) = 61600 numbers up to 77005 share no factor with it.
- 4
The digits of 77005 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 50 steps to reach 1.
LaTeX source of the formulas on this page
\[ 77005 = 5 \times 15401 \]
77005 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 92412 |
| Euler totient φ(n) | 61600 |
| Square | 5929770025 |
| Cube | 456621940775125 |
| Square root | 277.497748 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 50 |
| Scientific notation | 7.7005 × |
77005 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand and five |
| Binary (base 2) | 10010110011001101 |
| Octal (base 8) | 226315 |
| Hexadecimal (base 16) | 12CCD |
| Base 3 | 10220122001 |
| As time | 77005 seconds = 21 h 23 min 25 s |
Is 77005 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 | No (remainder 1) | 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 | Yes (77005 ÷ 5 = 15401) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | 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 | No (remainder 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | 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 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 77005 a prime number?
No. 77005 = 5 × 15401, so it is divisible by 5.
What are the factors of 77005?
1, 5, 15401, 77005.
What is 77005 in binary?
10010110011001101 (hexadecimal 12CCD, octal 226315).
What is the square root of 77005?
About 277.4977.
Is 77005 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 77005?
77005 is a semiprime: 5 × 15401, the product of two primes.