The number 15925
15925 is a composite number with 18 divisors. Its prime factorisation is × × 13. Divisors (18): 1, 5, 7, 13, 25, 35, 49, 65, 91, 175, 245, 325, 455, 637, 1225, 2275 … 15925.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
15925 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
15925 is composite. Its prime factorisation is
- 3
The divisors add up to 24738; without 15925 itself that is 8813, so 15925 is deficient (8813 is less than 15925). Euler's totient φ(15925) = 10080 numbers up to 15925 share no factor with it.
- 4
The digits of 15925 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 27 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15925 = 5^{2} \times 7^{2} \times 13 \]15925 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 18 |
| Sum of divisors | 24738 |
| Euler totient φ(n) | 10080 |
| Square | 253605625 |
| Cube | 4038669578125 |
| Square root | 126.194295 (= 35√13) |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 27 |
| Scientific notation | 1.5925 × |
15925 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand nine hundred and twenty-five |
| Binary (base 2) | 11111000110101 |
| Octal (base 8) | 37065 |
| Hexadecimal (base 16) | 3E35 |
| Base 3 | 210211211 |
| As time | 15925 seconds = 4 h 25 min 25 s |
Is 15925 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 1) | 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 (15925 ÷ 5 = 3185) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (15925 ÷ 7 = 2275) | 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 4) | 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 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 15925 a prime number?
No. 15925 = × × 13, so it is divisible by 5.
What are the factors of 15925?
1, 5, 7, 13, 25, 35, 49, 65, 91, 175, 245, 325, 455, 637, 1225, 2275, 3185, 15925.
What is 15925 in binary?
11111000110101 (hexadecimal 3E35, octal 37065).
What is the square root of 15925?
About 126.1943, exactly 35√13.
Is 15925 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 15925?
It is a composite number with 18 divisors.