The number 15440
15440 is a composite number with 20 divisors. Its prime factorisation is × 5 × 193. Divisors (20): 1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 193, 386, 772, 965, 1544, 1930 … 15440.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
15440 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
15440 is composite. Its prime factorisation is
- 3
The divisors add up to 36084; without 15440 itself that is 20644, so 15440 is abundant (20644 is more than 15440). Euler's totient φ(15440) = 6144 numbers up to 15440 share no factor with it.
- 4
The digits of 15440 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 27 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15440 = 2^{4} \times 5 \times 193 \]15440 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 20 |
| Sum of divisors | 36084 |
| Euler totient φ(n) | 6144 |
| Square | 238393600 |
| Cube | 3680797184000 |
| Square root | 124.257797 (= 4√965) |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 27 |
| Scientific notation | 1.544 × |
15440 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand four hundred and forty |
| Binary (base 2) | 11110001010000 |
| Octal (base 8) | 36120 |
| Hexadecimal (base 16) | 3C50 |
| Base 3 | 210011212 |
| As time | 15440 seconds = 4 h 17 min 20 s |
Is 15440 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (15440 ÷ 2 = 7720) | 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 (15440 ÷ 4 = 3860) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (15440 ÷ 5 = 3088) | 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 5) | 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 (15440 ÷ 8 = 1930) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (15440 ÷ 10 = 1544) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | 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 15440 a prime number?
No. 15440 = × 5 × 193, so it is divisible by 2.
What are the factors of 15440?
1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 193, 386, 772, 965, 1544, 1930, 3088, 3860, 7720, 15440.
What is 15440 in binary?
11110001010000 (hexadecimal 3C50, octal 36120).
What is the square root of 15440?
About 124.2578, exactly 4√965.
Is 15440 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 15440?
It is a composite number with 20 divisors.