The number 15565
15565 is a composite number with 8 divisors. Its prime factorisation is 5 × 11 × 283. Divisors (8): 1, 5, 11, 55, 283, 1415, 3113, 15565.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
15565 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
15565 is composite. Its prime factorisation is
- 3
The divisors add up to 20448; without 15565 itself that is 4883, so 15565 is deficient (4883 is less than 15565). Euler's totient φ(15565) = 11280 numbers up to 15565 share no factor with it.
- 4
The digits of 15565 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 40 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15565 = 5 \times 11 \times 283 \]
15565 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 20448 |
| Euler totient φ(n) | 11280 |
| Square | 242269225 |
| Cube | 3770920487125 |
| Square root | 124.759769 |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 40 |
| Scientific notation | 1.5565 × |
15565 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand five hundred and sixty-five |
| Binary (base 2) | 11110011001101 |
| Octal (base 8) | 36315 |
| Hexadecimal (base 16) | 3CCD |
| Base 3 | 210100111 |
| As time | 15565 seconds = 4 h 19 min 25 s |
Is 15565 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 (15565 ÷ 5 = 3113) | 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 4) | 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 | Yes (15565 ÷ 11 = 1415) | 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 15565 a prime number?
No. 15565 = 5 × 11 × 283, so it is divisible by 5.
What are the factors of 15565?
1, 5, 11, 55, 283, 1415, 3113, 15565.
What is 15565 in binary?
11110011001101 (hexadecimal 3CCD, octal 36315).
What is the square root of 15565?
About 124.7598.
Is 15565 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 15565?
It is a composite number with 8 divisors.