The number 12409
12409 is the 1481st prime number. Its only divisors are 1 and 12409.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 12409: the 1481st prime number.
- 2
12409 is prime, so its only factors are 1 and 12409. It is the 1481st prime; the next prime is 12413 and the one before is 12401.
- 3
The divisors add up to 12410; without 12409 itself that is 1, so 12409 is deficient (1 is less than 12409). Euler's totient φ(12409) = 12408 numbers up to 12409 share no factor with it.
- 4
The digits of 12409 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 94 steps to reach 1.
12409 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 12410 |
| Euler totient φ(n) | 12408 |
| Square | 153983281 |
| Cube | 1910778533929 |
| Square root | 111.395691 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 94 |
| Scientific notation | 1.2409 × |
12409 in other forms
| Form | Value |
|---|---|
| In words | twelve thousand four hundred and nine |
| Binary (base 2) | 11000001111001 |
| Octal (base 8) | 30171 |
| Hexadecimal (base 16) | 3079 |
| Base 3 | 122000121 |
| As time | 12409 seconds = 3 h 26 min 49 s |
Is 12409 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 | No (remainder 1) | 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 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 12409 a prime number?
Yes. 12409 is divisible only by 1 and itself.
What are the factors of 12409?
1, 12409.
What is 12409 in binary?
11000001111001 (hexadecimal 3079, octal 30171).
What is the square root of 12409?
About 111.3957.
Is 12409 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 12409?
12409 is the 1481st prime number.