The number 7989
7989 is a composite number with 4 divisors. Its prime factorisation is 3 × 2663. Divisors (4): 1, 3, 2663, 7989.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 7989: a semiprime: 3 × 2663, the product of two primes.
- 2
7989 is composite. Its prime factorisation is
- 3
The divisors add up to 10656; without 7989 itself that is 2667, so 7989 is deficient (2667 is less than 7989). Euler's totient φ(7989) = 5324 numbers up to 7989 share no factor with it.
- 4
The digits of 7989 add up to 33, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 52 steps to reach 1.
LaTeX source of the formulas on this page
\[ 7989 = 3 \times 2663 \]
7989 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 10656 |
| Euler totient φ(n) | 5324 |
| Square | 63824121 |
| Cube | 509890902669 |
| Square root | 89.381206 |
| Digit sum / digital root | 33 / 6 |
| Collatz steps to 1 | 52 |
| Scientific notation | 7.989 × |
7989 in other forms
| Form | Value |
|---|---|
| In words | seven thousand nine hundred and eighty-nine |
| Binary (base 2) | 1111100110101 |
| Octal (base 8) | 17465 |
| Hexadecimal (base 16) | 1F35 |
| Base 3 | 101221220 |
| As time | 7989 seconds = 2 h 13 min 9 s |
Is 7989 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 | Yes (7989 ÷ 3 = 2663) | 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 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 6) | 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 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 7989 a prime number?
No. 7989 = 3 × 2663, so it is divisible by 3.
What are the factors of 7989?
1, 3, 2663, 7989.
What is 7989 in binary?
1111100110101 (hexadecimal 1F35, octal 17465).
What is the square root of 7989?
About 89.3812.
Is 7989 divisible by 3?
Yes. Its digits add up to 33, a multiple of 3.
What is special about the number 7989?
7989 is a semiprime: 3 × 2663, the product of two primes.