The number 42090
42090 is a composite number with 32 divisors. Its prime factorisation is 2 × 3 × 5 × 23 × 61. Divisors (32): 1, 2, 3, 5, 6, 10, 15, 23, 30, 46, 61, 69, 115, 122, 138, 183 … 42090.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42090: a Harshad number: divisible by its digit sum 15.
- 2
42090 is composite. Its prime factorisation is
- 3
The divisors add up to 107136; without 42090 itself that is 65046, so 42090 is abundant (65046 is more than 42090). Euler's totient φ(42090) = 10560 numbers up to 42090 share no factor with it.
- 4
The digits of 42090 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 57 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42090 = 2 \times 3 \times 5 \times 23 \times 61 \]
42090 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 107136 |
| Euler totient φ(n) | 10560 |
| Square | 1771568100 |
| Cube | 74565301329000 |
| Square root | 205.158475 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 57 |
| Scientific notation | 4.209 × |
42090 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand and ninety |
| Binary (base 2) | 1010010001101010 |
| Octal (base 8) | 122152 |
| Hexadecimal (base 16) | A46A |
| Base 3 | 2010201220 |
| As time | 42090 seconds = 11 h 41 min 30 s |
Is 42090 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42090 ÷ 2 = 21045) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (42090 ÷ 3 = 14030) | 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 (42090 ÷ 5 = 8418) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (42090 ÷ 6 = 7015) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (42090 ÷ 10 = 4209) | 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 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42090 a prime number?
No. 42090 = 2 × 3 × 5 × 23 × 61, so it is divisible by 2.
What are the factors of 42090?
1, 2, 3, 5, 6, 10, 15, 23, 30, 46, 61, 69, 115, 122, 138, 183, 230, 305, 345, 366, 610, 690, 915, 1403, 1830, 2806, 4209, 7015, 8418, 14030, 21045, 42090.
What is 42090 in binary?
1010010001101010 (hexadecimal A46A, octal 122152).
What is the square root of 42090?
About 205.1585.
Is 42090 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 42090?
42090 is a Harshad number: divisible by its digit sum 15.