The number 72731
72731 is a composite number with 4 divisors. Its prime factorisation is 257 × 283. Divisors (4): 1, 257, 283, 72731.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72731: a semiprime: 257 × 283, the product of two primes.
- 2
72731 is composite. Its prime factorisation is
- 3
The divisors add up to 73272; without 72731 itself that is 541, so 72731 is deficient (541 is less than 72731). Euler's totient φ(72731) = 72192 numbers up to 72731 share no factor with it.
- 4
The digits of 72731 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 187 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72731 = 257 \times 283 \]
72731 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 73272 |
| Euler totient φ(n) | 72192 |
| Square | 5289798361 |
| Cube | 384732324593891 |
| Square root | 269.686855 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 187 |
| Scientific notation | 7.2731 × |
72731 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand seven hundred and thirty-one |
| Binary (base 2) | 10001110000011011 |
| Octal (base 8) | 216033 |
| Hexadecimal (base 16) | 11C1B |
| Base 3 | 10200202202 |
| As time | 72731 seconds = 20 h 12 min 11 s |
Is 72731 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 | No (remainder 2) | 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 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | 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 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72731 a prime number?
No. 72731 = 257 × 283, so it is divisible by 257.
What are the factors of 72731?
1, 257, 283, 72731.
What is 72731 in binary?
10001110000011011 (hexadecimal 11C1B, octal 216033).
What is the square root of 72731?
About 269.6869.
Is 72731 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 72731?
72731 is a semiprime: 257 × 283, the product of two primes.