The number 7901
7901 is the 998th prime number. Its only divisors are 1 and 7901.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 7901: the 998th prime number.
- 2
7901 is prime, so its only factors are 1 and 7901. It is the 998th prime; the next prime is 7907 and the one before is 7883.
- 3
The divisors add up to 7902; without 7901 itself that is 1, so 7901 is deficient (1 is less than 7901). Euler's totient φ(7901) = 7900 numbers up to 7901 share no factor with it.
- 4
The digits of 7901 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 39 steps to reach 1.
7901 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 7902 |
| Euler totient φ(n) | 7900 |
| Square | 62425801 |
| Cube | 493226253701 |
| Square root | 88.887569 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 39 |
| Scientific notation | 7.901 × |
7901 in other forms
| Form | Value |
|---|---|
| In words | seven thousand nine hundred and one |
| Binary (base 2) | 1111011011101 |
| Octal (base 8) | 17335 |
| Hexadecimal (base 16) | 1EDD |
| Base 3 | 101211122 |
| As time | 7901 seconds = 2 h 11 min 41 s |
Is 7901 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 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 8) | 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 3) | 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 7901 a prime number?
Yes. 7901 is divisible only by 1 and itself.
What are the factors of 7901?
1, 7901.
What is 7901 in binary?
1111011011101 (hexadecimal 1EDD, octal 17335).
What is the square root of 7901?
About 88.8876.
Is 7901 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 7901?
7901 is the 998th prime number.