The number 77801
77801 is the 7648th prime number and a binary palindrome (10010111111101001). Its only divisors are 1 and 77801.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 77801: the 7648th prime number; a binary palindrome (10010111111101001).
- 2
77801 is prime, so its only factors are 1 and 77801. It is the 7648th prime; the next prime is 77813 and the one before is 77797.
- 3
The divisors add up to 77802; without 77801 itself that is 1, so 77801 is deficient (1 is less than 77801). Euler's totient φ(77801) = 77800 numbers up to 77801 share no factor with it.
- 4
The digits of 77801 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 94 steps to reach 1.
77801 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 77802 |
| Euler totient φ(n) | 77800 |
| Square | 6052995601 |
| Cube | 470929110753401 |
| Square root | 278.928306 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 94 |
| Scientific notation | 7.7801 × |
77801 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand eight hundred and one |
| Binary (base 2) | 10010111111101001 |
| Octal (base 8) | 227751 |
| Hexadecimal (base 16) | 12FE9 |
| Base 3 | 10221201112 |
| As time | 77801 seconds = 21 h 36 min 41 s |
Is 77801 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 1) | 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 3) | 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 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 77801 a prime number?
Yes. 77801 is divisible only by 1 and itself.
What are the factors of 77801?
1, 77801.
What is 77801 in binary?
10010111111101001 (hexadecimal 12FE9, octal 227751).
What is the square root of 77801?
About 278.9283.
Is 77801 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 77801?
77801 is the 7648th prime number; a binary palindrome (10010111111101001).