The number 7290
7290 is a composite number with 28 divisors. Its prime factorisation is 2 × × 5. Divisors (28): 1, 2, 3, 5, 6, 9, 10, 15, 18, 27, 30, 45, 54, 81, 90, 135 … 7290.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 7290: a Harshad number: divisible by its digit sum 18.
- 2
7290 is composite. Its prime factorisation is
- 3
The divisors add up to 19674; without 7290 itself that is 12384, so 7290 is abundant (12384 is more than 7290). Euler's totient φ(7290) = 1944 numbers up to 7290 share no factor with it.
- 4
The digits of 7290 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 44 steps to reach 1.
LaTeX source of the formulas on this page
\[ 7290 = 2 \times 3^{6} \times 5 \]7290 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 28 |
| Sum of divisors | 19674 |
| Euler totient φ(n) | 1944 |
| Square | 53144100 |
| Cube | 387420489000 |
| Square root | 85.381497 (= 27√10) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 44 |
| Scientific notation | 7.29 × |
7290 in other forms
| Form | Value |
|---|---|
| In words | seven thousand two hundred and ninety |
| Binary (base 2) | 1110001111010 |
| Octal (base 8) | 16172 |
| Hexadecimal (base 16) | 1C7A |
| Base 3 | 101000000 |
| As time | 7290 seconds = 2 h 1 min 30 s |
Is 7290 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (7290 ÷ 2 = 3645) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (7290 ÷ 3 = 2430) | 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 (7290 ÷ 5 = 1458) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (7290 ÷ 6 = 1215) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (7290 ÷ 9 = 810) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (7290 ÷ 10 = 729) | 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 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 7290 a prime number?
No. 7290 = 2 × × 5, so it is divisible by 2.
What are the factors of 7290?
1, 2, 3, 5, 6, 9, 10, 15, 18, 27, 30, 45, 54, 81, 90, 135, 162, 243, 270, 405, 486, 729, 810, 1215, 1458, 2430, 3645, 7290.
What is 7290 in binary?
1110001111010 (hexadecimal 1C7A, octal 16172).
What is the square root of 7290?
About 85.3815, exactly 27√10.
Is 7290 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 7290?
7290 is a Harshad number: divisible by its digit sum 18.