The number 15980
15980 is a composite number with 24 divisors. Its prime factorisation is × 5 × 17 × 47. Divisors (24): 1, 2, 4, 5, 10, 17, 20, 34, 47, 68, 85, 94, 170, 188, 235, 340 … 15980.
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How to work it out
- 1
15980 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
15980 is composite. Its prime factorisation is
- 3
The divisors add up to 36288; without 15980 itself that is 20308, so 15980 is abundant (20308 is more than 15980). Euler's totient φ(15980) = 5888 numbers up to 15980 share no factor with it.
- 4
The digits of 15980 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 84 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15980 = 2^{2} \times 5 \times 17 \times 47 \]15980 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 36288 |
| Euler totient φ(n) | 5888 |
| Square | 255360400 |
| Cube | 4080659192000 |
| Square root | 126.412025 (= 2√3995) |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 84 |
| Scientific notation | 1.598 × |
15980 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand nine hundred and eighty |
| Binary (base 2) | 11111001101100 |
| Octal (base 8) | 37154 |
| Hexadecimal (base 16) | 3E6C |
| Base 3 | 210220212 |
| As time | 15980 seconds = 4 h 26 min 20 s |
Is 15980 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (15980 ÷ 2 = 7990) | 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 (15980 ÷ 4 = 3995) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (15980 ÷ 5 = 3196) | 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 6) | 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 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (15980 ÷ 10 = 1598) | 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 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 15980 a prime number?
No. 15980 = × 5 × 17 × 47, so it is divisible by 2.
What are the factors of 15980?
1, 2, 4, 5, 10, 17, 20, 34, 47, 68, 85, 94, 170, 188, 235, 340, 470, 799, 940, 1598, 3196, 3995, 7990, 15980.
What is 15980 in binary?
11111001101100 (hexadecimal 3E6C, octal 37154).
What is the square root of 15980?
About 126.4120, exactly 2√3995.
Is 15980 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 15980?
It is a composite number with 24 divisors.