The number 3909
3909 is a composite number with 4 divisors. Its prime factorisation is 3 × 1303. Divisors (4): 1, 3, 1303, 3909.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 3909: a semiprime: 3 × 1303, the product of two primes.
- 2
3909 is composite. Its prime factorisation is
- 3
The divisors add up to 5216; without 3909 itself that is 1307, so 3909 is deficient (1307 is less than 3909). Euler's totient φ(3909) = 2604 numbers up to 3909 share no factor with it.
- 4
The digits of 3909 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 100 steps to reach 1.
LaTeX source of the formulas on this page
\[ 3909 = 3 \times 1303 \]
3909 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 5216 |
| Euler totient φ(n) | 2604 |
| Square | 15280281 |
| Cube | 59730618429 |
| Square root | 62.521996 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 100 |
| Scientific notation | 3.909 × |
3909 in other forms
| Form | Value |
|---|---|
| In words | three thousand nine hundred and nine |
| Roman numerals | MMMCMIX |
| Binary (base 2) | 111101000101 |
| Octal (base 8) | 7505 |
| Hexadecimal (base 16) | F45 |
| Base 3 | 12100210 |
| As time | 3909 seconds = 1 h 5 min 9 s |
Is 3909 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 | Yes (3909 ÷ 3 = 1303) | 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 3) | 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 5) | 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 | No (remainder 9) | 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 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 3909 a prime number?
No. 3909 = 3 × 1303, so it is divisible by 3.
What are the factors of 3909?
1, 3, 1303, 3909.
What is 3909 in binary?
111101000101 (hexadecimal F45, octal 7505).
What is the square root of 3909?
About 62.5220.
What is 3909 in Roman numerals?
MMMCMIX.
Is 3909 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 3909?
3909 is a semiprime: 3 × 1303, the product of two primes.