The number 42195
42195 is a triangular number: 1 + 2 + … + 290 = 42195. Its prime factorisation is 3 × 5 × 29 × 97. Divisors (16): 1, 3, 5, 15, 29, 87, 97, 145, 291, 435, 485, 1455, 2813, 8439, 14065, 42195.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42195: a triangular number: 1 + 2 + … + 290 = 42195.
- 2
42195 is composite. Its prime factorisation is
- 3
The divisors add up to 70560; without 42195 itself that is 28365, so 42195 is deficient (28365 is less than 42195). Euler's totient φ(42195) = 21504 numbers up to 42195 share no factor with it.
- 4
The digits of 42195 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 80 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42195 = 3 \times 5 \times 29 \times 97 \]
42195 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 70560 |
| Euler totient φ(n) | 21504 |
| Square | 1780418025 |
| Cube | 75124738564875 |
| Square root | 205.414216 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 80 |
| Scientific notation | 4.2195 × |
42195 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand one hundred and ninety-five |
| Binary (base 2) | 1010010011010011 |
| Octal (base 8) | 122323 |
| Hexadecimal (base 16) | A4D3 |
| Base 3 | 2010212210 |
| As time | 42195 seconds = 11 h 43 min 15 s |
Is 42195 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 | Yes (42195 ÷ 3 = 14065) | 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 | Yes (42195 ÷ 5 = 8439) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42195 a prime number?
No. 42195 = 3 × 5 × 29 × 97, so it is divisible by 3.
What are the factors of 42195?
1, 3, 5, 15, 29, 87, 97, 145, 291, 435, 485, 1455, 2813, 8439, 14065, 42195.
What is 42195 in binary?
1010010011010011 (hexadecimal A4D3, octal 122323).
What is the square root of 42195?
About 205.4142.
Is 42195 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 42195?
42195 is a triangular number: 1 + 2 + … + 290 = 42195.