The number 33721
33721 is the 3611th prime number. Its only divisors are 1 and 33721.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 33721: the 3611th prime number.
- 2
33721 is prime, so its only factors are 1 and 33721. It is the 3611th prime; the next prime is 33739 and the one before is 33713.
- 3
The divisors add up to 33722; without 33721 itself that is 1, so 33721 is deficient (1 is less than 33721). Euler's totient φ(33721) = 33720 numbers up to 33721 share no factor with it.
- 4
The digits of 33721 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 59 steps to reach 1.
33721 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 33722 |
| Euler totient φ(n) | 33720 |
| Square | 1137105841 |
| Cube | 38344346064361 |
| Square root | 183.632786 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 59 |
| Scientific notation | 3.3721 × |
33721 in other forms
| Form | Value |
|---|---|
| In words | thirty-three thousand seven hundred and twenty-one |
| Binary (base 2) | 1000001110111001 |
| Octal (base 8) | 101671 |
| Hexadecimal (base 16) | 83B9 |
| Base 3 | 1201020221 |
| As time | 33721 seconds = 9 h 22 min 1 s |
Is 33721 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 2) | 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 1) | 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 6) | 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 33721 a prime number?
Yes. 33721 is divisible only by 1 and itself.
What are the factors of 33721?
1, 33721.
What is 33721 in binary?
1000001110111001 (hexadecimal 83B9, octal 101671).
What is the square root of 33721?
About 183.6328.
Is 33721 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 33721?
33721 is the 3611th prime number.