The number 142
142 is a composite number with 4 divisors. Its prime factorisation is 2 × 71. Divisors (4): 1, 2, 71, 142.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 142: a semiprime: 2 × 71, the product of two primes.
- 2
142 is composite. Its prime factorisation is
- 3
The divisors add up to 216; without 142 itself that is 74, so 142 is deficient (74 is less than 142). Euler's totient φ(142) = 70 numbers up to 142 share no factor with it.
- 4
The digits of 142 add up to 7, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 103 steps to reach 1.
LaTeX source of the formulas on this page
\[ 142 = 2 \times 71 \]
142 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 216 |
| Euler totient φ(n) | 70 |
| Square | 20164 |
| Cube | 2863288 |
| Square root | 11.916375 |
| Digit sum / digital root | 7 / 7 |
| Collatz steps to 1 | 103 |
| Scientific notation | 1.42 × |
142 in other forms
| Form | Value |
|---|---|
| In words | one hundred and forty-two |
| Roman numerals | CXLII |
| Binary (base 2) | 10001110 |
| Octal (base 8) | 216 |
| Hexadecimal (base 16) | 8E |
| Base 3 | 12021 |
| As time | 142 seconds = 2 min 22 s |
Is 142 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (142 ÷ 2 = 71) | 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 | No (remainder 2) | 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 2) | 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 7) | 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 10) | 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 142 a prime number?
No. 142 = 2 × 71, so it is divisible by 2.
What are the factors of 142?
1, 2, 71, 142.
What is 142 in binary?
10001110 (hexadecimal 8E, octal 216).
What is the square root of 142?
About 11.9164.
What is 142 in Roman numerals?
CXLII.
Is 142 divisible by 3?
No. Its digits add up to 7, which is not a multiple of 3.
What is special about the number 142?
142 is a semiprime: 2 × 71, the product of two primes.