The number 72381
72381 is a composite number with 8 divisors. Its prime factorisation is 3 × 23 × 1049. Divisors (8): 1, 3, 23, 69, 1049, 3147, 24127, 72381.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
72381 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
72381 is composite. Its prime factorisation is
- 3
The divisors add up to 100800; without 72381 itself that is 28419, so 72381 is deficient (28419 is less than 72381). Euler's totient φ(72381) = 46112 numbers up to 72381 share no factor with it.
- 4
The digits of 72381 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 143 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72381 = 3 \times 23 \times 1049 \]
72381 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 100800 |
| Euler totient φ(n) | 46112 |
| Square | 5239009161 |
| Cube | 379204722082341 |
| Square root | 269.037172 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 143 |
| Scientific notation | 7.2381 × |
72381 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand three hundred and eighty-one |
| Binary (base 2) | 10001101010111101 |
| Octal (base 8) | 215275 |
| Hexadecimal (base 16) | 11ABD |
| Base 3 | 10200021210 |
| As time | 72381 seconds = 20 h 6 min 21 s |
Is 72381 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 (72381 ÷ 3 = 24127) | 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 | No (remainder 1) | 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 1) | 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 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | 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 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72381 a prime number?
No. 72381 = 3 × 23 × 1049, so it is divisible by 3.
What are the factors of 72381?
1, 3, 23, 69, 1049, 3147, 24127, 72381.
What is 72381 in binary?
10001101010111101 (hexadecimal 11ABD, octal 215275).
What is the square root of 72381?
About 269.0372.
Is 72381 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 72381?
It is a composite number with 8 divisors.