The number 25540
25540 is a composite number with 12 divisors. Its prime factorisation is × 5 × 1277. Divisors (12): 1, 2, 4, 5, 10, 20, 1277, 2554, 5108, 6385, 12770, 25540.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 25540: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
25540 is composite. Its prime factorisation is
- 3
The divisors add up to 53676; without 25540 itself that is 28136, so 25540 is abundant (28136 is more than 25540). Euler's totient φ(25540) = 10208 numbers up to 25540 share no factor with it.
- 4
The digits of 25540 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 126 steps to reach 1.
LaTeX source of the formulas on this page
\[ 25540 = 2^{2} \times 5 \times 1277 \]25540 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 53676 |
| Euler totient φ(n) | 10208 |
| Square | 652291600 |
| Cube | 16659527464000 |
| Square root | 159.812390 (= 2√6385) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 126 |
| Scientific notation | 2.554 × |
25540 in other forms
| Form | Value |
|---|---|
| In words | twenty-five thousand five hundred and forty |
| Binary (base 2) | 110001111000100 |
| Octal (base 8) | 61704 |
| Hexadecimal (base 16) | 63C4 |
| Base 3 | 1022000221 |
| As time | 25540 seconds = 7 h 5 min 40 s |
Is 25540 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (25540 ÷ 2 = 12770) | 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 (25540 ÷ 4 = 6385) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (25540 ÷ 5 = 5108) | 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 4) | 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 4) | 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 | Yes (25540 ÷ 10 = 2554) | 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 25540 a prime number?
No. 25540 = × 5 × 1277, so it is divisible by 2.
What are the factors of 25540?
1, 2, 4, 5, 10, 20, 1277, 2554, 5108, 6385, 12770, 25540.
What is 25540 in binary?
110001111000100 (hexadecimal 63C4, octal 61704).
What is the square root of 25540?
About 159.8124, exactly 2√6385.
Is 25540 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 25540?
25540 is a happy number: repeatedly adding the squares of its digits reaches 1.