The number 36821
36821 is the 3905th prime number. Its only divisors are 1 and 36821.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 36821: the 3905th prime number.
- 2
36821 is prime, so its only factors are 1 and 36821. It is the 3905th prime; the next prime is 36833 and the one before is 36809.
- 3
The divisors add up to 36822; without 36821 itself that is 1, so 36821 is deficient (1 is less than 36821). Euler's totient φ(36821) = 36820 numbers up to 36821 share no factor with it.
- 4
The digits of 36821 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 49 steps to reach 1.
36821 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 36822 |
| Euler totient φ(n) | 36820 |
| Square | 1355786041 |
| Cube | 49921397815661 |
| Square root | 191.887988 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 49 |
| Scientific notation | 3.6821 × |
36821 in other forms
| Form | Value |
|---|---|
| In words | thirty-six thousand eight hundred and twenty-one |
| Binary (base 2) | 1000111111010101 |
| Octal (base 8) | 107725 |
| Hexadecimal (base 16) | 8FD5 |
| Base 3 | 1212111202 |
| As time | 36821 seconds = 10 h 13 min 41 s |
Is 36821 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 2) | 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 2) | 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 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 36821 a prime number?
Yes. 36821 is divisible only by 1 and itself.
What are the factors of 36821?
1, 36821.
What is 36821 in binary?
1000111111010101 (hexadecimal 8FD5, octal 107725).
What is the square root of 36821?
About 191.8880.
Is 36821 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 36821?
36821 is the 3905th prime number.