The number 72320
72320 is a composite number with 32 divisors. Its prime factorisation is × 5 × 113. Divisors (32): 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 113, 128, 160, 226 … 72320.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
72320 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
72320 is composite. Its prime factorisation is
- 3
The divisors add up to 174420; without 72320 itself that is 102100, so 72320 is abundant (102100 is more than 72320). Euler's totient φ(72320) = 28672 numbers up to 72320 share no factor with it.
- 4
The digits of 72320 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 24 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72320 = 2^{7} \times 5 \times 113 \]72320 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 174420 |
| Euler totient φ(n) | 28672 |
| Square | 5230182400 |
| Cube | 378246791168000 |
| Square root | 268.923781 (= 8√1130) |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 24 |
| Scientific notation | 7.232 × |
72320 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand three hundred and twenty |
| Binary (base 2) | 10001101010000000 |
| Octal (base 8) | 215200 |
| Hexadecimal (base 16) | 11A80 |
| Base 3 | 10200012112 |
| As time | 72320 seconds = 20 h 5 min 20 s |
Is 72320 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (72320 ÷ 2 = 36160) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (72320 ÷ 4 = 18080) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (72320 ÷ 5 = 14464) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 | Yes (72320 ÷ 8 = 9040) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (72320 ÷ 10 = 7232) | 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 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72320 a prime number?
No. 72320 = × 5 × 113, so it is divisible by 2.
What are the factors of 72320?
1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 113, 128, 160, 226, 320, 452, 565, 640, 904, 1130, 1808, 2260, 3616, 4520, 7232, 9040, 14464, 18080, 36160, 72320.
What is 72320 in binary?
10001101010000000 (hexadecimal 11A80, octal 215200).
What is the square root of 72320?
About 268.9238, exactly 8√1130.
Is 72320 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 72320?
It is a composite number with 32 divisors.