The number 7949
7949 is a twin prime (7949 and 7951 are both prime) and the 1004th prime number. Its only divisors are 1 and 7949.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 7949: a twin prime (7949 and 7951 are both prime); the 1004th prime number.
- 2
7949 is prime, so its only factors are 1 and 7949. It is the 1004th prime; the next prime is 7951 and the one before is 7937.
- 3
The divisors add up to 7950; without 7949 itself that is 1, so 7949 is deficient (1 is less than 7949). Euler's totient φ(7949) = 7948 numbers up to 7949 share no factor with it.
- 4
The digits of 7949 add up to 29, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 96 steps to reach 1.
7949 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 7950 |
| Euler totient φ(n) | 7948 |
| Square | 63186601 |
| Cube | 502270291349 |
| Square root | 89.157165 |
| Digit sum / digital root | 29 / 2 |
| Collatz steps to 1 | 96 |
| Scientific notation | 7.949 × |
7949 in other forms
| Form | Value |
|---|---|
| In words | seven thousand nine hundred and forty-nine |
| Binary (base 2) | 1111100001101 |
| Octal (base 8) | 17415 |
| Hexadecimal (base 16) | 1F0D |
| Base 3 | 101220102 |
| As time | 7949 seconds = 2 h 12 min 29 s |
Is 7949 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 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 4) | 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 2) | 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 7) | 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 7949 a prime number?
Yes. 7949 is divisible only by 1 and itself.
What are the factors of 7949?
1, 7949.
What is 7949 in binary?
1111100001101 (hexadecimal 1F0D, octal 17415).
What is the square root of 7949?
About 89.1572.
Is 7949 divisible by 3?
No. Its digits add up to 29, which is not a multiple of 3.
What is special about the number 7949?
7949 is a twin prime (7949 and 7951 are both prime); the 1004th prime number.