The number 87890
87890 is a composite number with 32 divisors. Its prime factorisation is 2 × 5 × 11 × 17 × 47. Divisors (32): 1, 2, 5, 10, 11, 17, 22, 34, 47, 55, 85, 94, 110, 170, 187, 235 … 87890.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
87890 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
87890 is composite. Its prime factorisation is
- 3
The divisors add up to 186624; without 87890 itself that is 98734, so 87890 is abundant (98734 is more than 87890). Euler's totient φ(87890) = 29440 numbers up to 87890 share no factor with it.
- 4
The digits of 87890 add up to 32, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 125 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87890 = 2 \times 5 \times 11 \times 17 \times 47 \]
87890 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 186624 |
| Euler totient φ(n) | 29440 |
| Square | 7724652100 |
| Cube | 678919673069000 |
| Square root | 296.462477 |
| Digit sum / digital root | 32 / 5 |
| Collatz steps to 1 | 125 |
| Scientific notation | 8.789 × |
87890 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand eight hundred and ninety |
| Binary (base 2) | 10101011101010010 |
| Octal (base 8) | 253522 |
| Hexadecimal (base 16) | 15752 |
| Base 3 | 11110120012 |
| As time | 87890 seconds = 24 h 24 min 50 s |
Is 87890 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (87890 ÷ 2 = 43945) | 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 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (87890 ÷ 5 = 17578) | 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 2) | 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 (87890 ÷ 10 = 8789) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (87890 ÷ 11 = 7990) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87890 a prime number?
No. 87890 = 2 × 5 × 11 × 17 × 47, so it is divisible by 2.
What are the factors of 87890?
1, 2, 5, 10, 11, 17, 22, 34, 47, 55, 85, 94, 110, 170, 187, 235, 374, 470, 517, 799, 935, 1034, 1598, 1870, 2585, 3995, 5170, 7990, 8789, 17578, 43945, 87890.
What is 87890 in binary?
10101011101010010 (hexadecimal 15752, octal 253522).
What is the square root of 87890?
About 296.4625.
Is 87890 divisible by 3?
No. Its digits add up to 32, which is not a multiple of 3.
What is special about the number 87890?
It is a composite number with 32 divisors.