The number 55215
55215 is a composite number with 16 divisors. Its prime factorisation is × 5 × 409. Divisors (16): 1, 3, 5, 9, 15, 27, 45, 135, 409, 1227, 2045, 3681, 6135, 11043, 18405, 55215.
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How to work it out
- 1
55215 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
55215 is composite. Its prime factorisation is
- 3
The divisors add up to 98400; without 55215 itself that is 43185, so 55215 is deficient (43185 is less than 55215). Euler's totient φ(55215) = 29376 numbers up to 55215 share no factor with it.
- 4
The digits of 55215 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 153 steps to reach 1.
LaTeX source of the formulas on this page
\[ 55215 = 3^{3} \times 5 \times 409 \]55215 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 98400 |
| Euler totient φ(n) | 29376 |
| Square | 3048696225 |
| Cube | 168333762063375 |
| Square root | 234.978722 (= 3√6135) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 153 |
| Scientific notation | 5.5215 × |
55215 in other forms
| Form | Value |
|---|---|
| In words | fifty-five thousand two hundred and fifteen |
| Binary (base 2) | 1101011110101111 |
| Octal (base 8) | 153657 |
| Hexadecimal (base 16) | D7AF |
| Base 3 | 2210202000 |
| As time | 55215 seconds = 15 h 20 min 15 s |
Is 55215 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 (55215 ÷ 3 = 18405) | 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 (55215 ÷ 5 = 11043) | 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 6) | 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 | Yes (55215 ÷ 9 = 6135) | 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 6) | 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 55215 a prime number?
No. 55215 = × 5 × 409, so it is divisible by 3.
What are the factors of 55215?
1, 3, 5, 9, 15, 27, 45, 135, 409, 1227, 2045, 3681, 6135, 11043, 18405, 55215.
What is 55215 in binary?
1101011110101111 (hexadecimal D7AF, octal 153657).
What is the square root of 55215?
About 234.9787, exactly 3√6135.
Is 55215 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 55215?
It is a composite number with 16 divisors.