The number 21701
21701 is the 2435th prime number. Its only divisors are 1 and 21701.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21701: the 2435th prime number.
- 2
21701 is prime, so its only factors are 1 and 21701. It is the 2435th prime; the next prime is 21713 and the one before is 21683.
- 3
The divisors add up to 21702; without 21701 itself that is 1, so 21701 is deficient (1 is less than 21701). Euler's totient φ(21701) = 21700 numbers up to 21701 share no factor with it.
- 4
The digits of 21701 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 162 steps to reach 1.
21701 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 21702 |
| Euler totient φ(n) | 21700 |
| Square | 470933401 |
| Cube | 10219725735101 |
| Square root | 147.312593 |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 162 |
| Scientific notation | 2.1701 × |
21701 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand seven hundred and one |
| Binary (base 2) | 101010011000101 |
| Octal (base 8) | 52305 |
| Hexadecimal (base 16) | 54C5 |
| Base 3 | 1002202202 |
| As time | 21701 seconds = 6 h 1 min 41 s |
Is 21701 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 9) | 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 21701 a prime number?
Yes. 21701 is divisible only by 1 and itself.
What are the factors of 21701?
1, 21701.
What is 21701 in binary?
101010011000101 (hexadecimal 54C5, octal 52305).
What is the square root of 21701?
About 147.3126.
Is 21701 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 21701?
21701 is the 2435th prime number.