The number 7409
7409 is a composite number with 4 divisors. Its prime factorisation is 31 × 239. Divisors (4): 1, 31, 239, 7409.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 7409: a semiprime: 31 × 239, the product of two primes.
- 2
7409 is composite. Its prime factorisation is
- 3
The divisors add up to 7680; without 7409 itself that is 271, so 7409 is deficient (271 is less than 7409). Euler's totient φ(7409) = 7140 numbers up to 7409 share no factor with it.
- 4
The digits of 7409 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 132 steps to reach 1.
LaTeX source of the formulas on this page
\[ 7409 = 31 \times 239 \]
7409 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 7680 |
| Euler totient φ(n) | 7140 |
| Square | 54893281 |
| Cube | 406704318929 |
| Square root | 86.075548 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 132 |
| Scientific notation | 7.409 × |
7409 in other forms
| Form | Value |
|---|---|
| In words | seven thousand four hundred and nine |
| Binary (base 2) | 1110011110001 |
| Octal (base 8) | 16361 |
| Hexadecimal (base 16) | 1CF1 |
| Base 3 | 101011102 |
| As time | 7409 seconds = 2 h 3 min 29 s |
Is 7409 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 2) | 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 5) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | 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 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 7409 a prime number?
No. 7409 = 31 × 239, so it is divisible by 31.
What are the factors of 7409?
1, 31, 239, 7409.
What is 7409 in binary?
1110011110001 (hexadecimal 1CF1, octal 16361).
What is the square root of 7409?
About 86.0755.
Is 7409 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 7409?
7409 is a semiprime: 31 × 239, the product of two primes.