The number 83821
83821 is a composite number with 4 divisors. Its prime factorisation is 109 × 769. Divisors (4): 1, 109, 769, 83821.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 83821: a semiprime: 109 × 769, the product of two primes.
- 2
83821 is composite. Its prime factorisation is
- 3
The divisors add up to 84700; without 83821 itself that is 879, so 83821 is deficient (879 is less than 83821). Euler's totient φ(83821) = 82944 numbers up to 83821 share no factor with it.
- 4
The digits of 83821 add up to 22, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 89 steps to reach 1.
LaTeX source of the formulas on this page
\[ 83821 = 109 \times 769 \]
83821 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 84700 |
| Euler totient φ(n) | 82944 |
| Square | 7025960041 |
| Cube | 588922996596661 |
| Square root | 289.518566 |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 89 |
| Scientific notation | 8.3821 × |
83821 in other forms
| Form | Value |
|---|---|
| In words | eighty-three thousand eight hundred and twenty-one |
| Binary (base 2) | 10100011101101101 |
| Octal (base 8) | 243555 |
| Hexadecimal (base 16) | 1476D |
| Base 3 | 11020222111 |
| As time | 83821 seconds = 23 h 17 min 1 s |
Is 83821 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 1) | 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 | No (remainder 3) | 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 4) | 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 1) | 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 83821 a prime number?
No. 83821 = 109 × 769, so it is divisible by 109.
What are the factors of 83821?
1, 109, 769, 83821.
What is 83821 in binary?
10100011101101101 (hexadecimal 1476D, octal 243555).
What is the square root of 83821?
About 289.5186.
Is 83821 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 83821?
83821 is a semiprime: 109 × 769, the product of two primes.