The number 55815
55815 is a composite number with 12 divisors. Its prime factorisation is 3 × 5 × . Divisors (12): 1, 3, 5, 15, 61, 183, 305, 915, 3721, 11163, 18605, 55815.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
55815 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
55815 is composite. Its prime factorisation is
- 3
The divisors add up to 90792; without 55815 itself that is 34977, so 55815 is deficient (34977 is less than 55815). Euler's totient φ(55815) = 29280 numbers up to 55815 share no factor with it.
- 4
The digits of 55815 add up to 24, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 65 steps to reach 1.
LaTeX source of the formulas on this page
\[ 55815 = 3 \times 5 \times 61^{2} \]55815 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 90792 |
| Euler totient φ(n) | 29280 |
| Square | 3115314225 |
| Cube | 173881263468375 |
| Square root | 236.251984 (= 61√15) |
| Digit sum / digital root | 24 / 6 |
| Collatz steps to 1 | 65 |
| Scientific notation | 5.5815 × |
55815 in other forms
| Form | Value |
|---|---|
| In words | fifty-five thousand eight hundred and fifteen |
| Binary (base 2) | 1101101000000111 |
| Octal (base 8) | 155007 |
| Hexadecimal (base 16) | DA07 |
| Base 3 | 2211120020 |
| As time | 55815 seconds = 15 h 30 min 15 s |
Is 55815 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 (55815 ÷ 3 = 18605) | 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 (55815 ÷ 5 = 11163) | 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 | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | 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 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 55815 a prime number?
No. 55815 = 3 × 5 × , so it is divisible by 3.
What are the factors of 55815?
1, 3, 5, 15, 61, 183, 305, 915, 3721, 11163, 18605, 55815.
What is 55815 in binary?
1101101000000111 (hexadecimal DA07, octal 155007).
What is the square root of 55815?
About 236.2520, exactly 61√15.
Is 55815 divisible by 3?
Yes. Its digits add up to 24, a multiple of 3.
What is special about the number 55815?
It is a composite number with 12 divisors.