The number 15740
15740 is a composite number with 12 divisors. Its prime factorisation is × 5 × 787. Divisors (12): 1, 2, 4, 5, 10, 20, 787, 1574, 3148, 3935, 7870, 15740.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 15740: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
15740 is composite. Its prime factorisation is
- 3
The divisors add up to 33096; without 15740 itself that is 17356, so 15740 is abundant (17356 is more than 15740). Euler's totient φ(15740) = 6288 numbers up to 15740 share no factor with it.
- 4
The digits of 15740 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 102 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15740 = 2^{2} \times 5 \times 787 \]15740 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 33096 |
| Euler totient φ(n) | 6288 |
| Square | 247747600 |
| Cube | 3899547224000 |
| Square root | 125.459157 (= 2√3935) |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 102 |
| Scientific notation | 1.574 × |
15740 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand seven hundred and forty |
| Binary (base 2) | 11110101111100 |
| Octal (base 8) | 36574 |
| Hexadecimal (base 16) | 3D7C |
| Base 3 | 210120222 |
| As time | 15740 seconds = 4 h 22 min 20 s |
Is 15740 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (15740 ÷ 2 = 7870) | 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 (15740 ÷ 4 = 3935) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (15740 ÷ 5 = 3148) | 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 4) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (15740 ÷ 10 = 1574) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | 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 15740 a prime number?
No. 15740 = × 5 × 787, so it is divisible by 2.
What are the factors of 15740?
1, 2, 4, 5, 10, 20, 787, 1574, 3148, 3935, 7870, 15740.
What is 15740 in binary?
11110101111100 (hexadecimal 3D7C, octal 36574).
What is the square root of 15740?
About 125.4592, exactly 2√3935.
Is 15740 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 15740?
15740 is a happy number: repeatedly adding the squares of its digits reaches 1.