The number 25725
25725 is a composite number with 24 divisors. Its prime factorisation is 3 × × . Divisors (24): 1, 3, 5, 7, 15, 21, 25, 35, 49, 75, 105, 147, 175, 245, 343, 525 … 25725.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 25725: a Harshad number: divisible by its digit sum 21.
- 2
25725 is composite. Its prime factorisation is
- 3
The divisors add up to 49600; without 25725 itself that is 23875, so 25725 is deficient (23875 is less than 25725). Euler's totient φ(25725) = 11760 numbers up to 25725 share no factor with it.
- 4
The digits of 25725 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 126 steps to reach 1.
LaTeX source of the formulas on this page
\[ 25725 = 3 \times 5^{2} \times 7^{3} \]25725 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 49600 |
| Euler totient φ(n) | 11760 |
| Square | 661775625 |
| Cube | 17024177953125 |
| Square root | 160.390149 (= 35√21) |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 126 |
| Scientific notation | 2.5725 × |
25725 in other forms
| Form | Value |
|---|---|
| In words | twenty-five thousand seven hundred and twenty-five |
| Binary (base 2) | 110010001111101 |
| Octal (base 8) | 62175 |
| Hexadecimal (base 16) | 647D |
| Base 3 | 1022021210 |
| As time | 25725 seconds = 7 h 8 min 45 s |
Is 25725 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (25725 ÷ 3 = 8575) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (25725 ÷ 5 = 5145) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (25725 ÷ 7 = 3675) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 25725 a prime number?
No. 25725 = 3 × × , so it is divisible by 3.
What are the factors of 25725?
1, 3, 5, 7, 15, 21, 25, 35, 49, 75, 105, 147, 175, 245, 343, 525, 735, 1029, 1225, 1715, 3675, 5145, 8575, 25725.
What is 25725 in binary?
110010001111101 (hexadecimal 647D, octal 62175).
What is the square root of 25725?
About 160.3901, exactly 35√21.
Is 25725 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 25725?
25725 is a Harshad number: divisible by its digit sum 21.