The number 25408
25408 is a composite number with 14 divisors. Its prime factorisation is × 397. Divisors (14): 1, 2, 4, 8, 16, 32, 64, 397, 794, 1588, 3176, 6352, 12704, 25408.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 25408: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
25408 is composite. Its prime factorisation is
- 3
The divisors add up to 50546; without 25408 itself that is 25138, so 25408 is deficient (25138 is less than 25408). Euler's totient φ(25408) = 12672 numbers up to 25408 share no factor with it.
- 4
The digits of 25408 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 33 steps to reach 1.
LaTeX source of the formulas on this page
\[ 25408 = 2^{6} \times 397 \]25408 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 14 |
| Sum of divisors | 50546 |
| Euler totient φ(n) | 12672 |
| Square | 645566464 |
| Cube | 16402552717312 |
| Square root | 159.398871 (= 8√397) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 33 |
| Scientific notation | 2.5408 × |
25408 in other forms
| Form | Value |
|---|---|
| In words | twenty-five thousand four hundred and eight |
| Binary (base 2) | 110001101000000 |
| Octal (base 8) | 61500 |
| Hexadecimal (base 16) | 6340 |
| Base 3 | 1021212001 |
| As time | 25408 seconds = 7 h 3 min 28 s |
Is 25408 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (25408 ÷ 2 = 12704) | 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 | Yes (25408 ÷ 4 = 6352) | 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 | 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 | Yes (25408 ÷ 8 = 3176) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | 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 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 25408 a prime number?
No. 25408 = × 397, so it is divisible by 2.
What are the factors of 25408?
1, 2, 4, 8, 16, 32, 64, 397, 794, 1588, 3176, 6352, 12704, 25408.
What is 25408 in binary?
110001101000000 (hexadecimal 6340, octal 61500).
What is the square root of 25408?
About 159.3989, exactly 8√397.
Is 25408 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 25408?
25408 is a happy number: repeatedly adding the squares of its digits reaches 1.