The number 42638
42638 is a composite number with 4 divisors. Its prime factorisation is 2 × 21319. Divisors (4): 1, 2, 21319, 42638.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42638: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 21319, the product of two primes.
- 2
42638 is composite. Its prime factorisation is
- 3
The divisors add up to 63960; without 42638 itself that is 21322, so 42638 is deficient (21322 is less than 42638). Euler's totient φ(42638) = 21318 numbers up to 42638 share no factor with it.
- 4
The digits of 42638 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 101 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42638 = 2 \times 21319 \]
42638 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 63960 |
| Euler totient φ(n) | 21318 |
| Square | 1817999044 |
| Cube | 77515843238072 |
| Square root | 206.489709 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 101 |
| Scientific notation | 4.2638 × |
42638 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand six hundred and thirty-eight |
| Binary (base 2) | 1010011010001110 |
| Octal (base 8) | 123216 |
| Hexadecimal (base 16) | A68E |
| Base 3 | 2011111012 |
| As time | 42638 seconds = 11 h 50 min 38 s |
Is 42638 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42638 ÷ 2 = 21319) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | 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 | No (remainder 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 5) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42638 a prime number?
No. 42638 = 2 × 21319, so it is divisible by 2.
What are the factors of 42638?
1, 2, 21319, 42638.
What is 42638 in binary?
1010011010001110 (hexadecimal A68E, octal 123216).
What is the square root of 42638?
About 206.4897.
Is 42638 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 42638?
42638 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 21319, the product of two primes.