The number 8642
8642 is a composite number with 8 divisors. Its prime factorisation is 2 × 29 × 149. Divisors (8): 1, 2, 29, 58, 149, 298, 4321, 8642.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
8642 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
8642 is composite. Its prime factorisation is
- 3
The divisors add up to 13500; without 8642 itself that is 4858, so 8642 is deficient (4858 is less than 8642). Euler's totient φ(8642) = 4144 numbers up to 8642 share no factor with it.
- 4
The digits of 8642 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 171 steps to reach 1.
LaTeX source of the formulas on this page
\[ 8642 = 2 \times 29 \times 149 \]
8642 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 13500 |
| Euler totient φ(n) | 4144 |
| Square | 74684164 |
| Cube | 645420545288 |
| Square root | 92.962358 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 171 |
| Scientific notation | 8.642 × |
8642 in other forms
| Form | Value |
|---|---|
| In words | eight thousand six hundred and forty-two |
| Binary (base 2) | 10000111000010 |
| Octal (base 8) | 20702 |
| Hexadecimal (base 16) | 21C2 |
| Base 3 | 102212002 |
| As time | 8642 seconds = 2 h 24 min 2 s |
Is 8642 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (8642 ÷ 2 = 4321) | 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 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | 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 2) | 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 2) | 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 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 8642 a prime number?
No. 8642 = 2 × 29 × 149, so it is divisible by 2.
What are the factors of 8642?
1, 2, 29, 58, 149, 298, 4321, 8642.
What is 8642 in binary?
10000111000010 (hexadecimal 21C2, octal 20702).
What is the square root of 8642?
About 92.9624.
Is 8642 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 8642?
It is a composite number with 8 divisors.