The number 42138
42138 is a composite number with 12 divisors. Its prime factorisation is 2 × × 2341. Divisors (12): 1, 2, 3, 6, 9, 18, 2341, 4682, 7023, 14046, 21069, 42138.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42138: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.
- 2
42138 is composite. Its prime factorisation is
- 3
The divisors add up to 91338; without 42138 itself that is 49200, so 42138 is abundant (49200 is more than 42138). Euler's totient φ(42138) = 14040 numbers up to 42138 share no factor with it.
- 4
The digits of 42138 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 44 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42138 = 2 \times 3^{2} \times 2341 \]42138 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 91338 |
| Euler totient φ(n) | 14040 |
| Square | 1775611044 |
| Cube | 74820698172072 |
| Square root | 205.275425 (= 3√4682) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 44 |
| Scientific notation | 4.2138 × |
42138 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand one hundred and thirty-eight |
| Binary (base 2) | 1010010010011010 |
| Octal (base 8) | 122232 |
| Hexadecimal (base 16) | A49A |
| Base 3 | 2010210200 |
| As time | 42138 seconds = 11 h 42 min 18 s |
Is 42138 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42138 ÷ 2 = 21069) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (42138 ÷ 3 = 14046) | 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 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (42138 ÷ 6 = 7023) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 | Yes (42138 ÷ 9 = 4682) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | 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 42138 a prime number?
No. 42138 = 2 × × 2341, so it is divisible by 2.
What are the factors of 42138?
1, 2, 3, 6, 9, 18, 2341, 4682, 7023, 14046, 21069, 42138.
What is 42138 in binary?
1010010010011010 (hexadecimal A49A, octal 122232).
What is the square root of 42138?
About 205.2754, exactly 3√4682.
Is 42138 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 42138?
42138 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.