The number 21319
21319 is a twin prime (21317 and 21319 are both prime) and the 2394th prime number. Its only divisors are 1 and 21319.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21319: a twin prime (21317 and 21319 are both prime); the 2394th prime number.
- 2
21319 is prime, so its only factors are 1 and 21319. It is the 2394th prime; the next prime is 21323 and the one before is 21317.
- 3
The divisors add up to 21320; without 21319 itself that is 1, so 21319 is deficient (1 is less than 21319). Euler's totient φ(21319) = 21318 numbers up to 21319 share no factor with it.
- 4
The digits of 21319 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 100 steps to reach 1.
21319 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 21320 |
| Euler totient φ(n) | 21318 |
| Square | 454499761 |
| Cube | 9689480404759 |
| Square root | 146.010274 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 100 |
| Scientific notation | 2.1319 × |
21319 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand three hundred and nineteen |
| Binary (base 2) | 101001101000111 |
| Octal (base 8) | 51507 |
| Hexadecimal (base 16) | 5347 |
| Base 3 | 1002020121 |
| As time | 21319 seconds = 5 h 55 min 19 s |
Is 21319 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 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | 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 4) | 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 7) | 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 9) | 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 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21319 a prime number?
Yes. 21319 is divisible only by 1 and itself.
What are the factors of 21319?
1, 21319.
What is 21319 in binary?
101001101000111 (hexadecimal 5347, octal 51507).
What is the square root of 21319?
About 146.0103.
Is 21319 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 21319?
21319 is a twin prime (21317 and 21319 are both prime); the 2394th prime number.