The number 72315
72315 is a composite number with 12 divisors. Its prime factorisation is × 5 × 1607. Divisors (12): 1, 3, 5, 9, 15, 45, 1607, 4821, 8035, 14463, 24105, 72315.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
72315 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
72315 is composite. Its prime factorisation is
- 3
The divisors add up to 125424; without 72315 itself that is 53109, so 72315 is deficient (53109 is less than 72315). Euler's totient φ(72315) = 38544 numbers up to 72315 share no factor with it.
- 4
The digits of 72315 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 187 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72315 = 3^{2} \times 5 \times 1607 \]72315 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 125424 |
| Euler totient φ(n) | 38544 |
| Square | 5229459225 |
| Cube | 378168343855875 |
| Square root | 268.914485 (= 3√8035) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 187 |
| Scientific notation | 7.2315 × |
72315 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand three hundred and fifteen |
| Binary (base 2) | 10001101001111011 |
| Octal (base 8) | 215173 |
| Hexadecimal (base 16) | 11A7B |
| Base 3 | 10200012100 |
| As time | 72315 seconds = 20 h 5 min 15 s |
Is 72315 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 (72315 ÷ 3 = 24105) | 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 (72315 ÷ 5 = 14463) | 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 5) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (72315 ÷ 9 = 8035) | 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 72315 a prime number?
No. 72315 = × 5 × 1607, so it is divisible by 3.
What are the factors of 72315?
1, 3, 5, 9, 15, 45, 1607, 4821, 8035, 14463, 24105, 72315.
What is 72315 in binary?
10001101001111011 (hexadecimal 11A7B, octal 215173).
What is the square root of 72315?
About 268.9145, exactly 3√8035.
Is 72315 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 72315?
It is a composite number with 12 divisors.