The number 77999
77999 is the 7662nd prime number. Its only divisors are 1 and 77999.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 77999: the 7662nd prime number.
- 2
77999 is prime, so its only factors are 1 and 77999. It is the 7662nd prime; the next prime is 78007 and the one before is 77983.
- 3
The divisors add up to 78000; without 77999 itself that is 1, so 77999 is deficient (1 is less than 77999). Euler's totient φ(77999) = 77998 numbers up to 77999 share no factor with it.
- 4
The digits of 77999 add up to 41, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 200 steps to reach 1.
77999 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 78000 |
| Euler totient φ(n) | 77998 |
| Square | 6083844001 |
| Cube | 474533748233999 |
| Square root | 279.283011 |
| Digit sum / digital root | 41 / 5 |
| Collatz steps to 1 | 200 |
| Scientific notation | 7.7999 × |
77999 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand nine hundred and ninety-nine |
| Binary (base 2) | 10011000010101111 |
| Octal (base 8) | 230257 |
| Hexadecimal (base 16) | 130AF |
| Base 3 | 10221222212 |
| As time | 77999 seconds = 21 h 39 min 59 s |
Is 77999 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 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | 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 5) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | 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 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 77999 a prime number?
Yes. 77999 is divisible only by 1 and itself.
What are the factors of 77999?
1, 77999.
What is 77999 in binary?
10011000010101111 (hexadecimal 130AF, octal 230257).
What is the square root of 77999?
About 279.2830.
Is 77999 divisible by 3?
No. Its digits add up to 41, which is not a multiple of 3.
What is special about the number 77999?
77999 is the 7662nd prime number.