The number 79989
79989 is a composite number with 16 divisors. Its prime factorisation is 3 × 7 × 13 × 293. Divisors (16): 1, 3, 7, 13, 21, 39, 91, 273, 293, 879, 2051, 3809, 6153, 11427, 26663, 79989.
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How to work it out
- 1
What is special about 79989: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
79989 is composite. Its prime factorisation is
- 3
The divisors add up to 131712; without 79989 itself that is 51723, so 79989 is deficient (51723 is less than 79989). Euler's totient φ(79989) = 42048 numbers up to 79989 share no factor with it.
- 4
The digits of 79989 add up to 42, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 94 steps to reach 1.
LaTeX source of the formulas on this page
\[ 79989 = 3 \times 7 \times 13 \times 293 \]
79989 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 131712 |
| Euler totient φ(n) | 42048 |
| Square | 6398240121 |
| Cube | 511788829038669 |
| Square root | 282.823266 |
| Digit sum / digital root | 42 / 6 |
| Collatz steps to 1 | 94 |
| Scientific notation | 7.9989 × |
79989 in other forms
| Form | Value |
|---|---|
| In words | seventy-nine thousand nine hundred and eighty-nine |
| Binary (base 2) | 10011100001110101 |
| Octal (base 8) | 234165 |
| Hexadecimal (base 16) | 13875 |
| Base 3 | 11001201120 |
| As time | 79989 seconds = 22 h 13 min 9 s |
Is 79989 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 (79989 ÷ 3 = 26663) | 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 | Yes (79989 ÷ 7 = 11427) | 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 8) | 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 79989 a prime number?
No. 79989 = 3 × 7 × 13 × 293, so it is divisible by 3.
What are the factors of 79989?
1, 3, 7, 13, 21, 39, 91, 273, 293, 879, 2051, 3809, 6153, 11427, 26663, 79989.
What is 79989 in binary?
10011100001110101 (hexadecimal 13875, octal 234165).
What is the square root of 79989?
About 282.8233.
Is 79989 divisible by 3?
Yes. Its digits add up to 42, a multiple of 3.
What is special about the number 79989?
79989 is a happy number: repeatedly adding the squares of its digits reaches 1.