The number 15988
15988 is a composite number with 12 divisors. Its prime factorisation is × 7 × 571. Divisors (12): 1, 2, 4, 7, 14, 28, 571, 1142, 2284, 3997, 7994, 15988.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
15988 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
15988 is composite. Its prime factorisation is
- 3
The divisors add up to 32032; without 15988 itself that is 16044, so 15988 is abundant (16044 is more than 15988). Euler's totient φ(15988) = 6840 numbers up to 15988 share no factor with it.
- 4
The digits of 15988 add up to 31, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 53 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15988 = 2^{2} \times 7 \times 571 \]15988 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 32032 |
| Euler totient φ(n) | 6840 |
| Square | 255616144 |
| Cube | 4086790910272 |
| Square root | 126.443663 (= 2√3997) |
| Digit sum / digital root | 31 / 4 |
| Collatz steps to 1 | 53 |
| Scientific notation | 1.5988 × |
15988 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand nine hundred and eighty-eight |
| Binary (base 2) | 11111001110100 |
| Octal (base 8) | 37164 |
| Hexadecimal (base 16) | 3E74 |
| Base 3 | 210221011 |
| As time | 15988 seconds = 4 h 26 min 28 s |
Is 15988 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (15988 ÷ 2 = 7994) | 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 (15988 ÷ 4 = 3997) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | 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 (15988 ÷ 7 = 2284) | 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 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | 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 15988 a prime number?
No. 15988 = × 7 × 571, so it is divisible by 2.
What are the factors of 15988?
1, 2, 4, 7, 14, 28, 571, 1142, 2284, 3997, 7994, 15988.
What is 15988 in binary?
11111001110100 (hexadecimal 3E74, octal 37164).
What is the square root of 15988?
About 126.4437, exactly 2√3997.
Is 15988 divisible by 3?
No. Its digits add up to 31, which is not a multiple of 3.
What is special about the number 15988?
It is a composite number with 12 divisors.