The number 25615
25615 is a composite number with 8 divisors. Its prime factorisation is 5 × 47 × 109. Divisors (8): 1, 5, 47, 109, 235, 545, 5123, 25615.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 25615: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
25615 is composite. Its prime factorisation is
- 3
The divisors add up to 31680; without 25615 itself that is 6065, so 25615 is deficient (6065 is less than 25615). Euler's totient φ(25615) = 19872 numbers up to 25615 share no factor with it.
- 4
The digits of 25615 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 82 steps to reach 1.
LaTeX source of the formulas on this page
\[ 25615 = 5 \times 47 \times 109 \]
25615 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 31680 |
| Euler totient φ(n) | 19872 |
| Square | 656128225 |
| Cube | 16806724483375 |
| Square root | 160.046868 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 82 |
| Scientific notation | 2.5615 × |
25615 in other forms
| Form | Value |
|---|---|
| In words | twenty-five thousand six hundred and fifteen |
| Binary (base 2) | 110010000001111 |
| Octal (base 8) | 62017 |
| Hexadecimal (base 16) | 640F |
| Base 3 | 1022010201 |
| As time | 25615 seconds = 7 h 6 min 55 s |
Is 25615 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 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (25615 ÷ 5 = 5123) | 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 | No (remainder 2) | 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 1) | 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 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 25615 a prime number?
No. 25615 = 5 × 47 × 109, so it is divisible by 5.
What are the factors of 25615?
1, 5, 47, 109, 235, 545, 5123, 25615.
What is 25615 in binary?
110010000001111 (hexadecimal 640F, octal 62017).
What is the square root of 25615?
About 160.0469.
Is 25615 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 25615?
25615 is a happy number: repeatedly adding the squares of its digits reaches 1.