The number 72090
72090 is a composite number with 40 divisors. Its prime factorisation is 2 × × 5 × 89. Divisors (40): 1, 2, 3, 5, 6, 9, 10, 15, 18, 27, 30, 45, 54, 81, 89, 90 … 72090.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72090: a Harshad number: divisible by its digit sum 18.
- 2
72090 is composite. Its prime factorisation is
- 3
The divisors add up to 196020; without 72090 itself that is 123930, so 72090 is abundant (123930 is more than 72090). Euler's totient φ(72090) = 19008 numbers up to 72090 share no factor with it.
- 4
The digits of 72090 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 42 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72090 = 2 \times 3^{4} \times 5 \times 89 \]72090 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 40 |
| Sum of divisors | 196020 |
| Euler totient φ(n) | 19008 |
| Square | 5196968100 |
| Cube | 374649430329000 |
| Square root | 268.495810 (= 9√890) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 42 |
| Scientific notation | 7.209 × |
72090 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand and ninety |
| Binary (base 2) | 10001100110011010 |
| Octal (base 8) | 214632 |
| Hexadecimal (base 16) | 1199A |
| Base 3 | 10122220000 |
| As time | 72090 seconds = 20 h 1 min 30 s |
Is 72090 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (72090 ÷ 2 = 36045) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (72090 ÷ 3 = 24030) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (72090 ÷ 5 = 14418) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (72090 ÷ 6 = 12015) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (72090 ÷ 9 = 8010) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (72090 ÷ 10 = 7209) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72090 a prime number?
No. 72090 = 2 × × 5 × 89, so it is divisible by 2.
What are the factors of 72090?
1, 2, 3, 5, 6, 9, 10, 15, 18, 27, 30, 45, 54, 81, 89, 90, 135, 162, 178, 267, 270, 405, 445, 534, 801, 810, 890, 1335, 1602, 2403, 2670, 4005, 4806, 7209, 8010, 12015, 14418, 24030, 36045, 72090.
What is 72090 in binary?
10001100110011010 (hexadecimal 1199A, octal 214632).
What is the square root of 72090?
About 268.4958, exactly 9√890.
Is 72090 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 72090?
72090 is a Harshad number: divisible by its digit sum 18.