The number 72509
72509 is a composite number with 4 divisors. Its prime factorisation is 31 × 2339. Divisors (4): 1, 31, 2339, 72509.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72509: a semiprime: 31 × 2339, the product of two primes.
- 2
72509 is composite. Its prime factorisation is
- 3
The divisors add up to 74880; without 72509 itself that is 2371, so 72509 is deficient (2371 is less than 72509). Euler's totient φ(72509) = 70140 numbers up to 72509 share no factor with it.
- 4
The digits of 72509 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 94 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72509 = 31 \times 2339 \]
72509 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 74880 |
| Euler totient φ(n) | 70140 |
| Square | 5257555081 |
| Cube | 381220061368229 |
| Square root | 269.274952 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 94 |
| Scientific notation | 7.2509 × |
72509 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand five hundred and nine |
| Binary (base 2) | 10001101100111101 |
| Octal (base 8) | 215475 |
| Hexadecimal (base 16) | 11B3D |
| Base 3 | 10200110112 |
| As time | 72509 seconds = 20 h 8 min 29 s |
Is 72509 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 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | 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 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 | No (remainder 5) | 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 | No (remainder 9) | 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72509 a prime number?
No. 72509 = 31 × 2339, so it is divisible by 31.
What are the factors of 72509?
1, 31, 2339, 72509.
What is 72509 in binary?
10001101100111101 (hexadecimal 11B3D, octal 215475).
What is the square root of 72509?
About 269.2750.
Is 72509 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 72509?
72509 is a semiprime: 31 × 2339, the product of two primes.