The number 15540
15540 is a composite number with 48 divisors. Its prime factorisation is × 3 × 5 × 7 × 37. Divisors (48): 1, 2, 3, 4, 5, 6, 7, 10, 12, 14, 15, 20, 21, 28, 30, 35 … 15540.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 15540: a Harshad number: divisible by its digit sum 15.
- 2
15540 is composite. Its prime factorisation is
- 3
The divisors add up to 51072; without 15540 itself that is 35532, so 15540 is abundant (35532 is more than 15540). Euler's totient φ(15540) = 3456 numbers up to 15540 share no factor with it.
- 4
The digits of 15540 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 40 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15540 = 2^{2} \times 3 \times 5 \times 7 \times 37 \]15540 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 48 |
| Sum of divisors | 51072 |
| Euler totient φ(n) | 3456 |
| Square | 241491600 |
| Cube | 3752779464000 |
| Square root | 124.659536 (= 2√3885) |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 40 |
| Scientific notation | 1.554 × |
15540 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand five hundred and forty |
| Binary (base 2) | 11110010110100 |
| Octal (base 8) | 36264 |
| Hexadecimal (base 16) | 3CB4 |
| Base 3 | 210022120 |
| As time | 15540 seconds = 4 h 19 min 0 s |
Is 15540 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (15540 ÷ 2 = 7770) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (15540 ÷ 3 = 5180) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (15540 ÷ 4 = 3885) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (15540 ÷ 5 = 3108) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (15540 ÷ 6 = 2590) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (15540 ÷ 7 = 2220) | 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 6) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (15540 ÷ 10 = 1554) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (15540 ÷ 12 = 1295) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 15540 a prime number?
No. 15540 = × 3 × 5 × 7 × 37, so it is divisible by 2.
What are the factors of 15540?
1, 2, 3, 4, 5, 6, 7, 10, 12, 14, 15, 20, 21, 28, 30, 35, 37, 42, 60, 70, 74, 84, 105, 111, 140, 148, 185, 210, 222, 259, 370, 420, 444, 518, 555, 740, 777, 1036, 1110, 1295, 1554, 2220, 2590, 3108, 3885, 5180, 7770, 15540.
What is 15540 in binary?
11110010110100 (hexadecimal 3CB4, octal 36264).
What is the square root of 15540?
About 124.6595, exactly 2√3885.
Is 15540 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 15540?
15540 is a Harshad number: divisible by its digit sum 15.