The number 87428
87428 is a composite number with 12 divisors. Its prime factorisation is × 11 × 1987. Divisors (12): 1, 2, 4, 11, 22, 44, 1987, 3974, 7948, 21857, 43714, 87428.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
87428 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
87428 is composite. Its prime factorisation is
- 3
The divisors add up to 166992; without 87428 itself that is 79564, so 87428 is deficient (79564 is less than 87428). Euler's totient φ(87428) = 39720 numbers up to 87428 share no factor with it.
- 4
The digits of 87428 add up to 29, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 58 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87428 = 2^{2} \times 11 \times 1987 \]87428 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 166992 |
| Euler totient φ(n) | 39720 |
| Square | 7643655184 |
| Cube | 668269485426752 |
| Square root | 295.682262 (= 2√21857) |
| Digit sum / digital root | 29 / 2 |
| Collatz steps to 1 | 58 |
| Scientific notation | 8.7428 × |
87428 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand four hundred and twenty-eight |
| Binary (base 2) | 10101010110000100 |
| Octal (base 8) | 252604 |
| Hexadecimal (base 16) | 15584 |
| Base 3 | 11102221002 |
| As time | 87428 seconds = 24 h 17 min 8 s |
Is 87428 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (87428 ÷ 2 = 43714) | 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 (87428 ÷ 4 = 21857) | 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 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 | No (remainder 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | 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 | Yes (87428 ÷ 11 = 7948) | 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 87428 a prime number?
No. 87428 = × 11 × 1987, so it is divisible by 2.
What are the factors of 87428?
1, 2, 4, 11, 22, 44, 1987, 3974, 7948, 21857, 43714, 87428.
What is 87428 in binary?
10101010110000100 (hexadecimal 15584, octal 252604).
What is the square root of 87428?
About 295.6823, exactly 2√21857.
Is 87428 divisible by 3?
No. Its digits add up to 29, which is not a multiple of 3.
What is special about the number 87428?
It is a composite number with 12 divisors.