The number 15409
15409 is a composite number with 4 divisors. Its prime factorisation is 19 × 811. Divisors (4): 1, 19, 811, 15409.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 15409: a Harshad number: divisible by its digit sum 19; a semiprime: 19 × 811, the product of two primes.
- 2
15409 is composite. Its prime factorisation is
- 3
The divisors add up to 16240; without 15409 itself that is 831, so 15409 is deficient (831 is less than 15409). Euler's totient φ(15409) = 14580 numbers up to 15409 share no factor with it.
- 4
The digits of 15409 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 146 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15409 = 19 \times 811 \]
15409 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 16240 |
| Euler totient φ(n) | 14580 |
| Square | 237437281 |
| Cube | 3658671062929 |
| Square root | 124.132993 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 146 |
| Scientific notation | 1.5409 × |
15409 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand four hundred and nine |
| Binary (base 2) | 11110000110001 |
| Octal (base 8) | 36061 |
| Hexadecimal (base 16) | 3C31 |
| Base 3 | 210010201 |
| As time | 15409 seconds = 4 h 16 min 49 s |
Is 15409 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 2) | 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 1) | 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 9) | 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 15409 a prime number?
No. 15409 = 19 × 811, so it is divisible by 19.
What are the factors of 15409?
1, 19, 811, 15409.
What is 15409 in binary?
11110000110001 (hexadecimal 3C31, octal 36061).
What is the square root of 15409?
About 124.1330.
Is 15409 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 15409?
15409 is a Harshad number: divisible by its digit sum 19; a semiprime: 19 × 811, the product of two primes.