The number 25438
25438 is a composite number with 16 divisors. Its prime factorisation is 2 × 7 × 23 × 79. Divisors (16): 1, 2, 7, 14, 23, 46, 79, 158, 161, 322, 553, 1106, 1817, 3634, 12719, 25438.
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How to work it out
- 1
25438 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
25438 is composite. Its prime factorisation is
- 3
The divisors add up to 46080; without 25438 itself that is 20642, so 25438 is deficient (20642 is less than 25438). Euler's totient φ(25438) = 10296 numbers up to 25438 share no factor with it.
- 4
The digits of 25438 add up to 22, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 82 steps to reach 1.
LaTeX source of the formulas on this page
\[ 25438 = 2 \times 7 \times 23 \times 79 \]
25438 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 46080 |
| Euler totient φ(n) | 10296 |
| Square | 647091844 |
| Cube | 16460722327672 |
| Square root | 159.492947 |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 82 |
| Scientific notation | 2.5438 × |
25438 in other forms
| Form | Value |
|---|---|
| In words | twenty-five thousand four hundred and thirty-eight |
| Binary (base 2) | 110001101011110 |
| Octal (base 8) | 61536 |
| Hexadecimal (base 16) | 635E |
| Base 3 | 1021220011 |
| As time | 25438 seconds = 7 h 3 min 58 s |
Is 25438 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (25438 ÷ 2 = 12719) | 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 3) | 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 | Yes (25438 ÷ 7 = 3634) | 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 4) | 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 6) | 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 25438 a prime number?
No. 25438 = 2 × 7 × 23 × 79, so it is divisible by 2.
What are the factors of 25438?
1, 2, 7, 14, 23, 46, 79, 158, 161, 322, 553, 1106, 1817, 3634, 12719, 25438.
What is 25438 in binary?
110001101011110 (hexadecimal 635E, octal 61536).
What is the square root of 25438?
About 159.4929.
Is 25438 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 25438?
It is a composite number with 16 divisors.