The number 15904
15904 is a composite number with 24 divisors. Its prime factorisation is × 7 × 71. Divisors (24): 1, 2, 4, 7, 8, 14, 16, 28, 32, 56, 71, 112, 142, 224, 284, 497 … 15904.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
15904 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
15904 is composite. Its prime factorisation is
- 3
The divisors add up to 36288; without 15904 itself that is 20384, so 15904 is abundant (20384 is more than 15904). Euler's totient φ(15904) = 6720 numbers up to 15904 share no factor with it.
- 4
The digits of 15904 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 27 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15904 = 2^{5} \times 7 \times 71 \]15904 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 36288 |
| Euler totient φ(n) | 6720 |
| Square | 252937216 |
| Cube | 4022713483264 |
| Square root | 126.111062 (= 4√994) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 27 |
| Scientific notation | 1.5904 × |
15904 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand nine hundred and four |
| Binary (base 2) | 11111000100000 |
| Octal (base 8) | 37040 |
| Hexadecimal (base 16) | 3E20 |
| Base 3 | 210211001 |
| As time | 15904 seconds = 4 h 25 min 4 s |
Is 15904 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (15904 ÷ 2 = 7952) | 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 | Yes (15904 ÷ 4 = 3976) | 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 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (15904 ÷ 7 = 2272) | 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 (15904 ÷ 8 = 1988) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | 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 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 15904 a prime number?
No. 15904 = × 7 × 71, so it is divisible by 2.
What are the factors of 15904?
1, 2, 4, 7, 8, 14, 16, 28, 32, 56, 71, 112, 142, 224, 284, 497, 568, 994, 1136, 1988, 2272, 3976, 7952, 15904.
What is 15904 in binary?
11111000100000 (hexadecimal 3E20, octal 37040).
What is the square root of 15904?
About 126.1111, exactly 4√994.
Is 15904 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 15904?
It is a composite number with 24 divisors.