The number 72765
72765 is a composite number with 48 divisors. Its prime factorisation is × 5 × × 11. Divisors (48): 1, 3, 5, 7, 9, 11, 15, 21, 27, 33, 35, 45, 49, 55, 63, 77 … 72765.
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How to work it out
- 1
What is special about 72765: a Harshad number: divisible by its digit sum 27.
- 2
72765 is composite. Its prime factorisation is
- 3
The divisors add up to 164160; without 72765 itself that is 91395, so 72765 is abundant (91395 is more than 72765). Euler's totient φ(72765) = 30240 numbers up to 72765 share no factor with it.
- 4
The digits of 72765 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 143 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72765 = 3^{3} \times 5 \times 7^{2} \times 11 \]72765 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 48 |
| Sum of divisors | 164160 |
| Euler totient φ(n) | 30240 |
| Square | 5294745225 |
| Cube | 385272136297125 |
| Square root | 269.749884 (= 21√165) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 143 |
| Scientific notation | 7.2765 × |
72765 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand seven hundred and sixty-five |
| Binary (base 2) | 10001110000111101 |
| Octal (base 8) | 216075 |
| Hexadecimal (base 16) | 11C3D |
| Base 3 | 10200211000 |
| As time | 72765 seconds = 20 h 12 min 45 s |
Is 72765 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 (72765 ÷ 3 = 24255) | 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 (72765 ÷ 5 = 14553) | 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 (72765 ÷ 7 = 10395) | 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 | Yes (72765 ÷ 9 = 8085) | 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 | Yes (72765 ÷ 11 = 6615) | 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 72765 a prime number?
No. 72765 = × 5 × × 11, so it is divisible by 3.
What are the factors of 72765?
1, 3, 5, 7, 9, 11, 15, 21, 27, 33, 35, 45, 49, 55, 63, 77, 99, 105, 135, 147, 165, 189, 231, 245, 297, 315, 385, 441, 495, 539, 693, 735, 945, 1155, 1323, 1485, 1617, 2079, 2205, 2695, 3465, 4851, 6615, 8085, 10395, 14553, 24255, 72765.
What is 72765 in binary?
10001110000111101 (hexadecimal 11C3D, octal 216075).
What is the square root of 72765?
About 269.7499, exactly 21√165.
Is 72765 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 72765?
72765 is a Harshad number: divisible by its digit sum 27.