The number 9090
9090 is a composite number with 24 divisors. Its prime factorisation is 2 × × 5 × 101. Divisors (24): 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90, 101, 202, 303, 505 … 9090.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 9090: a Harshad number: divisible by its digit sum 18.
- 2
9090 is composite. Its prime factorisation is
- 3
The divisors add up to 23868; without 9090 itself that is 14778, so 9090 is abundant (14778 is more than 9090). Euler's totient φ(9090) = 2400 numbers up to 9090 share no factor with it.
- 4
The digits of 9090 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 140 steps to reach 1.
LaTeX source of the formulas on this page
\[ 9090 = 2 \times 3^{2} \times 5 \times 101 \]9090 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 23868 |
| Euler totient φ(n) | 2400 |
| Square | 82628100 |
| Cube | 751089429000 |
| Square root | 95.341491 (= 3√1010) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 140 |
| Scientific notation | 9.09 × |
9090 in other forms
| Form | Value |
|---|---|
| In words | nine thousand and ninety |
| Binary (base 2) | 10001110000010 |
| Octal (base 8) | 21602 |
| Hexadecimal (base 16) | 2382 |
| Base 3 | 110110200 |
| As time | 9090 seconds = 2 h 31 min 30 s |
Is 9090 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (9090 ÷ 2 = 4545) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (9090 ÷ 3 = 3030) | 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 (9090 ÷ 5 = 1818) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (9090 ÷ 6 = 1515) | 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 (9090 ÷ 9 = 1010) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (9090 ÷ 10 = 909) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | 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 9090 a prime number?
No. 9090 = 2 × × 5 × 101, so it is divisible by 2.
What are the factors of 9090?
1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90, 101, 202, 303, 505, 606, 909, 1010, 1515, 1818, 3030, 4545, 9090.
What is 9090 in binary?
10001110000010 (hexadecimal 2382, octal 21602).
What is the square root of 9090?
About 95.3415, exactly 3√1010.
Is 9090 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 9090?
9090 is a Harshad number: divisible by its digit sum 18.