The number 15725
15725 is a composite number with 12 divisors. Its prime factorisation is × 17 × 37. Divisors (12): 1, 5, 17, 25, 37, 85, 185, 425, 629, 925, 3145, 15725.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
15725 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
15725 is composite. Its prime factorisation is
- 3
The divisors add up to 21204; without 15725 itself that is 5479, so 15725 is deficient (5479 is less than 15725). Euler's totient φ(15725) = 11520 numbers up to 15725 share no factor with it.
- 4
The digits of 15725 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 84 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15725 = 5^{2} \times 17 \times 37 \]15725 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 21204 |
| Euler totient φ(n) | 11520 |
| Square | 247275625 |
| Cube | 3888409203125 |
| Square root | 125.399362 (= 5√629) |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 84 |
| Scientific notation | 1.5725 × |
15725 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand seven hundred and twenty-five |
| Binary (base 2) | 11110101101101 |
| Octal (base 8) | 36555 |
| Hexadecimal (base 16) | 3D6D |
| Base 3 | 210120102 |
| As time | 15725 seconds = 4 h 22 min 5 s |
Is 15725 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 | No (remainder 2) | 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 (15725 ÷ 5 = 3145) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 2) | 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 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 15725 a prime number?
No. 15725 = × 17 × 37, so it is divisible by 5.
What are the factors of 15725?
1, 5, 17, 25, 37, 85, 185, 425, 629, 925, 3145, 15725.
What is 15725 in binary?
11110101101101 (hexadecimal 3D6D, octal 36555).
What is the square root of 15725?
About 125.3994, exactly 5√629.
Is 15725 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 15725?
It is a composite number with 12 divisors.