The number 25415
25415 is a composite number with 16 divisors. Its prime factorisation is 5 × 13 × 17 × 23. Divisors (16): 1, 5, 13, 17, 23, 65, 85, 115, 221, 299, 391, 1105, 1495, 1955, 5083, 25415.
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How to work it out
- 1
What is special about 25415: a Harshad number: divisible by its digit sum 17.
- 2
25415 is composite. Its prime factorisation is
- 3
The divisors add up to 36288; without 25415 itself that is 10873, so 25415 is deficient (10873 is less than 25415). Euler's totient φ(25415) = 16896 numbers up to 25415 share no factor with it.
- 4
The digits of 25415 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 56 steps to reach 1.
LaTeX source of the formulas on this page
\[ 25415 = 5 \times 13 \times 17 \times 23 \]
25415 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 36288 |
| Euler totient φ(n) | 16896 |
| Square | 645922225 |
| Cube | 16416113348375 |
| Square root | 159.420827 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 56 |
| Scientific notation | 2.5415 × |
25415 in other forms
| Form | Value |
|---|---|
| In words | twenty-five thousand four hundred and fifteen |
| Binary (base 2) | 110001101000111 |
| Octal (base 8) | 61507 |
| Hexadecimal (base 16) | 6347 |
| Base 3 | 1021212022 |
| As time | 25415 seconds = 7 h 3 min 35 s |
Is 25415 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 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (25415 ÷ 5 = 5083) | 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 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 | No (remainder 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | 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 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 25415 a prime number?
No. 25415 = 5 × 13 × 17 × 23, so it is divisible by 5.
What are the factors of 25415?
1, 5, 13, 17, 23, 65, 85, 115, 221, 299, 391, 1105, 1495, 1955, 5083, 25415.
What is 25415 in binary?
110001101000111 (hexadecimal 6347, octal 61507).
What is the square root of 25415?
About 159.4208.
Is 25415 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 25415?
25415 is a Harshad number: divisible by its digit sum 17.