The number 67821
67821 is a composite number with 16 divisors. Its prime factorisation is 3 × 13 × 37 × 47. Divisors (16): 1, 3, 13, 37, 39, 47, 111, 141, 481, 611, 1443, 1739, 1833, 5217, 22607, 67821.
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How to work it out
- 1
67821 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
67821 is composite. Its prime factorisation is
- 3
The divisors add up to 102144; without 67821 itself that is 34323, so 67821 is deficient (34323 is less than 67821). Euler's totient φ(67821) = 39744 numbers up to 67821 share no factor with it.
- 4
The digits of 67821 add up to 24, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 86 steps to reach 1.
LaTeX source of the formulas on this page
\[ 67821 = 3 \times 13 \times 37 \times 47 \]
67821 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 102144 |
| Euler totient φ(n) | 39744 |
| Square | 4599688041 |
| Cube | 311955442628661 |
| Square root | 260.424653 |
| Digit sum / digital root | 24 / 6 |
| Collatz steps to 1 | 86 |
| Scientific notation | 6.7821 × |
67821 in other forms
| Form | Value |
|---|---|
| In words | sixty-seven thousand eight hundred and twenty-one |
| Binary (base 2) | 10000100011101101 |
| Octal (base 8) | 204355 |
| Hexadecimal (base 16) | 108ED |
| Base 3 | 10110000220 |
| As time | 67821 seconds = 18 h 50 min 21 s |
Is 67821 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 (67821 ÷ 3 = 22607) | 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 1) | 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 5) | 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 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | 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 67821 a prime number?
No. 67821 = 3 × 13 × 37 × 47, so it is divisible by 3.
What are the factors of 67821?
1, 3, 13, 37, 39, 47, 111, 141, 481, 611, 1443, 1739, 1833, 5217, 22607, 67821.
What is 67821 in binary?
10000100011101101 (hexadecimal 108ED, octal 204355).
What is the square root of 67821?
About 260.4247.
Is 67821 divisible by 3?
Yes. Its digits add up to 24, a multiple of 3.
What is special about the number 67821?
It is a composite number with 16 divisors.