The number 7904
7904 is a composite number with 24 divisors. Its prime factorisation is × 13 × 19. Divisors (24): 1, 2, 4, 8, 13, 16, 19, 26, 32, 38, 52, 76, 104, 152, 208, 247 … 7904.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
7904 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
7904 is composite. Its prime factorisation is
- 3
The divisors add up to 17640; without 7904 itself that is 9736, so 7904 is abundant (9736 is more than 7904). Euler's totient φ(7904) = 3456 numbers up to 7904 share no factor with it.
- 4
The digits of 7904 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 52 steps to reach 1.
LaTeX source of the formulas on this page
\[ 7904 = 2^{5} \times 13 \times 19 \]7904 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 17640 |
| Euler totient φ(n) | 3456 |
| Square | 62473216 |
| Cube | 493788299264 |
| Square root | 88.904443 (= 4√494) |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 52 |
| Scientific notation | 7.904 × |
7904 in other forms
| Form | Value |
|---|---|
| In words | seven thousand nine hundred and four |
| Binary (base 2) | 1111011100000 |
| Octal (base 8) | 17340 |
| Hexadecimal (base 16) | 1EE0 |
| Base 3 | 101211202 |
| As time | 7904 seconds = 2 h 11 min 44 s |
Is 7904 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (7904 ÷ 2 = 3952) | 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 | Yes (7904 ÷ 4 = 1976) | 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 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 | Yes (7904 ÷ 8 = 988) | 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 4) | 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 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 7904 a prime number?
No. 7904 = × 13 × 19, so it is divisible by 2.
What are the factors of 7904?
1, 2, 4, 8, 13, 16, 19, 26, 32, 38, 52, 76, 104, 152, 208, 247, 304, 416, 494, 608, 988, 1976, 3952, 7904.
What is 7904 in binary?
1111011100000 (hexadecimal 1EE0, octal 17340).
What is the square root of 7904?
About 88.9044, exactly 4√494.
Is 7904 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 7904?
It is a composite number with 24 divisors.