The number 87829
87829 is a composite number with 4 divisors. Its prime factorisation is 7 × 12547. Divisors (4): 1, 7, 12547, 87829.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 87829: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 7 × 12547, the product of two primes.
- 2
87829 is composite. Its prime factorisation is
- 3
The divisors add up to 100384; without 87829 itself that is 12555, so 87829 is deficient (12555 is less than 87829). Euler's totient φ(87829) = 75276 numbers up to 87829 share no factor with it.
- 4
The digits of 87829 add up to 34, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 133 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87829 = 7 \times 12547 \]
87829 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 100384 |
| Euler totient φ(n) | 75276 |
| Square | 7713933241 |
| Cube | 677507042623789 |
| Square root | 296.359579 |
| Digit sum / digital root | 34 / 7 |
| Collatz steps to 1 | 133 |
| Scientific notation | 8.7829 × |
87829 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand eight hundred and twenty-nine |
| Binary (base 2) | 10101011100010101 |
| Octal (base 8) | 253425 |
| Hexadecimal (base 16) | 15715 |
| Base 3 | 11110110221 |
| As time | 87829 seconds = 24 h 23 min 49 s |
Is 87829 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 1) | 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (87829 ÷ 7 = 12547) | 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 7) | 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 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87829 a prime number?
No. 87829 = 7 × 12547, so it is divisible by 7.
What are the factors of 87829?
1, 7, 12547, 87829.
What is 87829 in binary?
10101011100010101 (hexadecimal 15715, octal 253425).
What is the square root of 87829?
About 296.3596.
Is 87829 divisible by 3?
No. Its digits add up to 34, which is not a multiple of 3.
What is special about the number 87829?
87829 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 7 × 12547, the product of two primes.