The number 32821
32821 is a composite number with 4 divisors. Its prime factorisation is 23 × 1427. Divisors (4): 1, 23, 1427, 32821.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 32821: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 23 × 1427, the product of two primes.
- 2
32821 is composite. Its prime factorisation is
- 3
The divisors add up to 34272; without 32821 itself that is 1451, so 32821 is deficient (1451 is less than 32821). Euler's totient φ(32821) = 31372 numbers up to 32821 share no factor with it.
- 4
The digits of 32821 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 41 steps to reach 1.
LaTeX source of the formulas on this page
\[ 32821 = 23 \times 1427 \]
32821 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 34272 |
| Euler totient φ(n) | 31372 |
| Square | 1077218041 |
| Cube | 35355373323661 |
| Square root | 181.165670 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 41 |
| Scientific notation | 3.2821 × |
32821 in other forms
| Form | Value |
|---|---|
| In words | thirty-two thousand eight hundred and twenty-one |
| Binary (base 2) | 1000000000110101 |
| Octal (base 8) | 100065 |
| Hexadecimal (base 16) | 8035 |
| Base 3 | 1200000121 |
| As time | 32821 seconds = 9 h 7 min 1 s |
Is 32821 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 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 7) | 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 8) | 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 32821 a prime number?
No. 32821 = 23 × 1427, so it is divisible by 23.
What are the factors of 32821?
1, 23, 1427, 32821.
What is 32821 in binary?
1000000000110101 (hexadecimal 8035, octal 100065).
What is the square root of 32821?
About 181.1657.
Is 32821 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 32821?
32821 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 23 × 1427, the product of two primes.