The number 5565
5565 is a triangular number: 1 + 2 + … + 105 = 5565. Its prime factorisation is 3 × 5 × 7 × 53. Divisors (16): 1, 3, 5, 7, 15, 21, 35, 53, 105, 159, 265, 371, 795, 1113, 1855, 5565.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 5565: a triangular number: 1 + 2 + … + 105 = 5565; a Harshad number: divisible by its digit sum 21.
- 2
5565 is composite. Its prime factorisation is
- 3
The divisors add up to 10368; without 5565 itself that is 4803, so 5565 is deficient (4803 is less than 5565). Euler's totient φ(5565) = 2496 numbers up to 5565 share no factor with it.
- 4
The digits of 5565 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 116 steps to reach 1.
LaTeX source of the formulas on this page
\[ 5565 = 3 \times 5 \times 7 \times 53 \]
5565 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 10368 |
| Euler totient φ(n) | 2496 |
| Square | 30969225 |
| Cube | 172343737125 |
| Square root | 74.598928 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 116 |
| Scientific notation | 5.565 × |
5565 in other forms
| Form | Value |
|---|---|
| In words | five thousand five hundred and sixty-five |
| Binary (base 2) | 1010110111101 |
| Octal (base 8) | 12675 |
| Hexadecimal (base 16) | 15BD |
| Base 3 | 21122010 |
| As time | 5565 seconds = 1 h 32 min 45 s |
Is 5565 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 | Yes (5565 ÷ 3 = 1855) | 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 (5565 ÷ 5 = 1113) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (5565 ÷ 7 = 795) | 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 3) | 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 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 5565 a prime number?
No. 5565 = 3 × 5 × 7 × 53, so it is divisible by 3.
What are the factors of 5565?
1, 3, 5, 7, 15, 21, 35, 53, 105, 159, 265, 371, 795, 1113, 1855, 5565.
What is 5565 in binary?
1010110111101 (hexadecimal 15BD, octal 12675).
What is the square root of 5565?
About 74.5989.
Is 5565 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 5565?
5565 is a triangular number: 1 + 2 + … + 105 = 5565; a Harshad number: divisible by its digit sum 21.