The number 72135
72135 is a composite number with 24 divisors. Its prime factorisation is × 5 × 7 × 229. Divisors (24): 1, 3, 5, 7, 9, 15, 21, 35, 45, 63, 105, 229, 315, 687, 1145, 1603 … 72135.
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How to work it out
- 1
72135 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
72135 is composite. Its prime factorisation is
- 3
The divisors add up to 143520; without 72135 itself that is 71385, so 72135 is deficient (71385 is less than 72135). Euler's totient φ(72135) = 32832 numbers up to 72135 share no factor with it.
- 4
The digits of 72135 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 125 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72135 = 3^{2} \times 5 \times 7 \times 229 \]72135 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 143520 |
| Euler totient φ(n) | 32832 |
| Square | 5203458225 |
| Cube | 375351459060375 |
| Square root | 268.579597 (= 3√8015) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 125 |
| Scientific notation | 7.2135 × |
72135 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand one hundred and thirty-five |
| Binary (base 2) | 10001100111000111 |
| Octal (base 8) | 214707 |
| Hexadecimal (base 16) | 119C7 |
| Base 3 | 10122221200 |
| As time | 72135 seconds = 20 h 2 min 15 s |
Is 72135 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 (72135 ÷ 3 = 24045) | 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 (72135 ÷ 5 = 14427) | 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 (72135 ÷ 7 = 10305) | 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 (72135 ÷ 9 = 8015) | 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 8) | 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 72135 a prime number?
No. 72135 = × 5 × 7 × 229, so it is divisible by 3.
What are the factors of 72135?
1, 3, 5, 7, 9, 15, 21, 35, 45, 63, 105, 229, 315, 687, 1145, 1603, 2061, 3435, 4809, 8015, 10305, 14427, 24045, 72135.
What is 72135 in binary?
10001100111000111 (hexadecimal 119C7, octal 214707).
What is the square root of 72135?
About 268.5796, exactly 3√8015.
Is 72135 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 72135?
It is a composite number with 24 divisors.