The number 21190
21190 is a composite number with 16 divisors. Its prime factorisation is 2 × 5 × 13 × 163. Divisors (16): 1, 2, 5, 10, 13, 26, 65, 130, 163, 326, 815, 1630, 2119, 4238, 10595, 21190.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21190: a Harshad number: divisible by its digit sum 13.
- 2
21190 is composite. Its prime factorisation is
- 3
The divisors add up to 41328; without 21190 itself that is 20138, so 21190 is deficient (20138 is less than 21190). Euler's totient φ(21190) = 7776 numbers up to 21190 share no factor with it.
- 4
The digits of 21190 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 100 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21190 = 2 \times 5 \times 13 \times 163 \]
21190 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 41328 |
| Euler totient φ(n) | 7776 |
| Square | 449016100 |
| Cube | 9514651159000 |
| Square root | 145.567854 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 100 |
| Scientific notation | 2.119 × |
21190 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand one hundred and ninety |
| Binary (base 2) | 101001011000110 |
| Octal (base 8) | 51306 |
| Hexadecimal (base 16) | 52C6 |
| Base 3 | 1002001211 |
| As time | 21190 seconds = 5 h 53 min 10 s |
Is 21190 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21190 ÷ 2 = 10595) | 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 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (21190 ÷ 5 = 4238) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | 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 6) | 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 | Yes (21190 ÷ 10 = 2119) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21190 a prime number?
No. 21190 = 2 × 5 × 13 × 163, so it is divisible by 2.
What are the factors of 21190?
1, 2, 5, 10, 13, 26, 65, 130, 163, 326, 815, 1630, 2119, 4238, 10595, 21190.
What is 21190 in binary?
101001011000110 (hexadecimal 52C6, octal 51306).
What is the square root of 21190?
About 145.5679.
Is 21190 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 21190?
21190 is a Harshad number: divisible by its digit sum 13.