The number 42790
42790 is a composite number with 16 divisors. Its prime factorisation is 2 × 5 × 11 × 389. Divisors (16): 1, 2, 5, 10, 11, 22, 55, 110, 389, 778, 1945, 3890, 4279, 8558, 21395, 42790.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42790: a Harshad number: divisible by its digit sum 22.
- 2
42790 is composite. Its prime factorisation is
- 3
The divisors add up to 84240; without 42790 itself that is 41450, so 42790 is deficient (41450 is less than 42790). Euler's totient φ(42790) = 15520 numbers up to 42790 share no factor with it.
- 4
The digits of 42790 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 194 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42790 = 2 \times 5 \times 11 \times 389 \]
42790 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 84240 |
| Euler totient φ(n) | 15520 |
| Square | 1830984100 |
| Cube | 78347809639000 |
| Square root | 206.857439 |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 194 |
| Scientific notation | 4.279 × |
42790 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand seven hundred and ninety |
| Binary (base 2) | 1010011100100110 |
| Octal (base 8) | 123446 |
| Hexadecimal (base 16) | A726 |
| Base 3 | 2011200211 |
| As time | 42790 seconds = 11 h 53 min 10 s |
Is 42790 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42790 ÷ 2 = 21395) | 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 (42790 ÷ 5 = 8558) | 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 6) | 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 (42790 ÷ 10 = 4279) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (42790 ÷ 11 = 3890) | 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 42790 a prime number?
No. 42790 = 2 × 5 × 11 × 389, so it is divisible by 2.
What are the factors of 42790?
1, 2, 5, 10, 11, 22, 55, 110, 389, 778, 1945, 3890, 4279, 8558, 21395, 42790.
What is 42790 in binary?
1010011100100110 (hexadecimal A726, octal 123446).
What is the square root of 42790?
About 206.8574.
Is 42790 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 42790?
42790 is a Harshad number: divisible by its digit sum 22.