The number 72045
72045 is a composite number with 12 divisors. Its prime factorisation is × 5 × 1601. Divisors (12): 1, 3, 5, 9, 15, 45, 1601, 4803, 8005, 14409, 24015, 72045.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72045: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
72045 is composite. Its prime factorisation is
- 3
The divisors add up to 124956; without 72045 itself that is 52911, so 72045 is deficient (52911 is less than 72045). Euler's totient φ(72045) = 38400 numbers up to 72045 share no factor with it.
- 4
The digits of 72045 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 68 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72045 = 3^{2} \times 5 \times 1601 \]72045 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 124956 |
| Euler totient φ(n) | 38400 |
| Square | 5190482025 |
| Cube | 373948277491125 |
| Square root | 268.411997 (= 3√8005) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 68 |
| Scientific notation | 7.2045 × |
72045 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand and forty-five |
| Binary (base 2) | 10001100101101101 |
| Octal (base 8) | 214555 |
| Hexadecimal (base 16) | 1196D |
| Base 3 | 10122211100 |
| As time | 72045 seconds = 20 h 0 min 45 s |
Is 72045 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 (72045 ÷ 3 = 24015) | 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 (72045 ÷ 5 = 14409) | 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 | Yes (72045 ÷ 9 = 8005) | 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 | No (remainder 6) | 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 72045 a prime number?
No. 72045 = × 5 × 1601, so it is divisible by 3.
What are the factors of 72045?
1, 3, 5, 9, 15, 45, 1601, 4803, 8005, 14409, 24015, 72045.
What is 72045 in binary?
10001100101101101 (hexadecimal 1196D, octal 214555).
What is the square root of 72045?
About 268.4120, exactly 3√8005.
Is 72045 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 72045?
72045 is a happy number: repeatedly adding the squares of its digits reaches 1.