The number 21673
21673 is the 2433rd prime number. Its only divisors are 1 and 21673.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21673: the 2433rd prime number.
- 2
21673 is prime, so its only factors are 1 and 21673. It is the 2433rd prime; the next prime is 21683 and the one before is 21661.
- 3
The divisors add up to 21674; without 21673 itself that is 1, so 21673 is deficient (1 is less than 21673). Euler's totient φ(21673) = 21672 numbers up to 21673 share no factor with it.
- 4
The digits of 21673 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 193 steps to reach 1.
21673 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 21674 |
| Euler totient φ(n) | 21672 |
| Square | 469718929 |
| Cube | 10180218348217 |
| Square root | 147.217526 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 193 |
| Scientific notation | 2.1673 × |
21673 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand six hundred and seventy-three |
| Binary (base 2) | 101010010101001 |
| Octal (base 8) | 52251 |
| Hexadecimal (base 16) | 54A9 |
| Base 3 | 1002201201 |
| As time | 21673 seconds = 6 h 1 min 13 s |
Is 21673 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 3) | 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 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 3) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | 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 21673 a prime number?
Yes. 21673 is divisible only by 1 and itself.
What are the factors of 21673?
1, 21673.
What is 21673 in binary?
101010010101001 (hexadecimal 54A9, octal 52251).
What is the square root of 21673?
About 147.2175.
Is 21673 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 21673?
21673 is the 2433rd prime number.