The number 342
342 is a composite number with 12 divisors. Its prime factorisation is 2 × × 19. Divisors (12): 1, 2, 3, 6, 9, 18, 19, 38, 57, 114, 171, 342.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 342: a Harshad number: divisible by its digit sum 9.
- 2
342 is composite. Its prime factorisation is
- 3
The divisors add up to 780; without 342 itself that is 438, so 342 is abundant (438 is more than 342). Euler's totient φ(342) = 108 numbers up to 342 share no factor with it.
- 4
The digits of 342 add up to 9, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 125 steps to reach 1.
LaTeX source of the formulas on this page
\[ 342 = 2 \times 3^{2} \times 19 \]342 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 780 |
| Euler totient φ(n) | 108 |
| Square | 116964 |
| Cube | 40001688 |
| Square root | 18.493242 (= 3√38) |
| Digit sum / digital root | 9 / 9 |
| Collatz steps to 1 | 125 |
| Scientific notation | 3.42 × |
342 in other forms
| Form | Value |
|---|---|
| In words | three hundred and forty-two |
| Roman numerals | CCCXLII |
| Binary (base 2) | 101010110 |
| Octal (base 8) | 526 |
| Hexadecimal (base 16) | 156 |
| Base 3 | 110200 |
| As time | 342 seconds = 5 min 42 s |
Is 342 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (342 ÷ 2 = 171) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (342 ÷ 3 = 114) | 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 | No (remainder 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (342 ÷ 6 = 57) | 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 | Yes (342 ÷ 9 = 38) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | 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 342 a prime number?
No. 342 = 2 × × 19, so it is divisible by 2.
What are the factors of 342?
1, 2, 3, 6, 9, 18, 19, 38, 57, 114, 171, 342.
What is 342 in binary?
101010110 (hexadecimal 156, octal 526).
What is the square root of 342?
About 18.4932, exactly 3√38.
What is 342 in Roman numerals?
CCCXLII.
Is 342 divisible by 3?
Yes. Its digits add up to 9, a multiple of 3.
What is special about the number 342?
342 is a Harshad number: divisible by its digit sum 9.