The number 77813
77813 is the 7649th prime number. Its only divisors are 1 and 77813.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 77813: the 7649th prime number.
- 2
77813 is prime, so its only factors are 1 and 77813. It is the 7649th prime; the next prime is 77839 and the one before is 77801.
- 3
The divisors add up to 77814; without 77813 itself that is 1, so 77813 is deficient (1 is less than 77813). Euler's totient φ(77813) = 77812 numbers up to 77813 share no factor with it.
- 4
The digits of 77813 add up to 26, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 94 steps to reach 1.
77813 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 77814 |
| Euler totient φ(n) | 77812 |
| Square | 6054862969 |
| Cube | 471147052206797 |
| Square root | 278.949816 |
| Digit sum / digital root | 26 / 8 |
| Collatz steps to 1 | 94 |
| Scientific notation | 7.7813 × |
77813 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand eight hundred and thirteen |
| Binary (base 2) | 10010111111110101 |
| Octal (base 8) | 227765 |
| Hexadecimal (base 16) | 12FF5 |
| Base 3 | 10221201222 |
| As time | 77813 seconds = 21 h 36 min 53 s |
Is 77813 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 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | 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 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 3) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 77813 a prime number?
Yes. 77813 is divisible only by 1 and itself.
What are the factors of 77813?
1, 77813.
What is 77813 in binary?
10010111111110101 (hexadecimal 12FF5, octal 227765).
What is the square root of 77813?
About 278.9498.
Is 77813 divisible by 3?
No. Its digits add up to 26, which is not a multiple of 3.
What is special about the number 77813?
77813 is the 7649th prime number.