The number 21199
21199 is a composite number with 8 divisors. Its prime factorisation is 17 × 29 × 43. Divisors (8): 1, 17, 29, 43, 493, 731, 1247, 21199.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21199 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21199 is composite. Its prime factorisation is
- 3
The divisors add up to 23760; without 21199 itself that is 2561, so 21199 is deficient (2561 is less than 21199). Euler's totient φ(21199) = 18816 numbers up to 21199 share no factor with it.
- 4
The digits of 21199 add up to 22, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 162 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21199 = 17 \times 29 \times 43 \]
21199 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 23760 |
| Euler totient φ(n) | 18816 |
| Square | 449397601 |
| Cube | 9526779743599 |
| Square root | 145.598764 |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 162 |
| Scientific notation | 2.1199 × |
21199 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand one hundred and ninety-nine |
| Binary (base 2) | 101001011001111 |
| Octal (base 8) | 51317 |
| Hexadecimal (base 16) | 52CF |
| Base 3 | 1002002011 |
| As time | 21199 seconds = 5 h 53 min 19 s |
Is 21199 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 3) | 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 4) | 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 2) | 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 21199 a prime number?
No. 21199 = 17 × 29 × 43, so it is divisible by 17.
What are the factors of 21199?
1, 17, 29, 43, 493, 731, 1247, 21199.
What is 21199 in binary?
101001011001111 (hexadecimal 52CF, octal 51317).
What is the square root of 21199?
About 145.5988.
Is 21199 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 21199?
It is a composite number with 8 divisors.