The number 12990
12990 is a composite number with 16 divisors. Its prime factorisation is 2 × 3 × 5 × 433. Divisors (16): 1, 2, 3, 5, 6, 10, 15, 30, 433, 866, 1299, 2165, 2598, 4330, 6495, 12990.
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How to work it out
- 1
What is special about 12990: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
12990 is composite. Its prime factorisation is
- 3
The divisors add up to 31248; without 12990 itself that is 18258, so 12990 is abundant (18258 is more than 12990). Euler's totient φ(12990) = 3456 numbers up to 12990 share no factor with it.
- 4
The digits of 12990 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 50 steps to reach 1.
LaTeX source of the formulas on this page
\[ 12990 = 2 \times 3 \times 5 \times 433 \]
12990 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 31248 |
| Euler totient φ(n) | 3456 |
| Square | 168740100 |
| Cube | 2191933899000 |
| Square root | 113.973681 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 50 |
| Scientific notation | 1.299 × |
12990 in other forms
| Form | Value |
|---|---|
| In words | twelve thousand nine hundred and ninety |
| Binary (base 2) | 11001010111110 |
| Octal (base 8) | 31276 |
| Hexadecimal (base 16) | 32BE |
| Base 3 | 122211010 |
| As time | 12990 seconds = 3 h 36 min 30 s |
Is 12990 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (12990 ÷ 2 = 6495) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (12990 ÷ 3 = 4330) | 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 (12990 ÷ 5 = 2598) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (12990 ÷ 6 = 2165) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (12990 ÷ 10 = 1299) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | 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 12990 a prime number?
No. 12990 = 2 × 3 × 5 × 433, so it is divisible by 2.
What are the factors of 12990?
1, 2, 3, 5, 6, 10, 15, 30, 433, 866, 1299, 2165, 2598, 4330, 6495, 12990.
What is 12990 in binary?
11001010111110 (hexadecimal 32BE, octal 31276).
What is the square root of 12990?
About 113.9737.
Is 12990 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 12990?
12990 is a happy number: repeatedly adding the squares of its digits reaches 1.