The number 87988
87988 is a composite number with 6 divisors. Its prime factorisation is × 21997. Divisors (6): 1, 2, 4, 21997, 43994, 87988.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
87988 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
87988 is composite. Its prime factorisation is
- 3
The divisors add up to 153986; without 87988 itself that is 65998, so 87988 is deficient (65998 is less than 87988). Euler's totient φ(87988) = 43992 numbers up to 87988 share no factor with it.
- 4
The digits of 87988 add up to 40, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 71 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87988 = 2^{2} \times 21997 \]87988 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 153986 |
| Euler totient φ(n) | 43992 |
| Square | 7741888144 |
| Cube | 681193254014272 |
| Square root | 296.627713 (= 2√21997) |
| Digit sum / digital root | 40 / 4 |
| Collatz steps to 1 | 71 |
| Scientific notation | 8.7988 × |
87988 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand nine hundred and eighty-eight |
| Binary (base 2) | 10101011110110100 |
| Octal (base 8) | 253664 |
| Hexadecimal (base 16) | 157B4 |
| Base 3 | 11110200211 |
| As time | 87988 seconds = 24 h 26 min 28 s |
Is 87988 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (87988 ÷ 2 = 43994) | 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 (87988 ÷ 4 = 21997) | 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 | 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 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 10) | 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 87988 a prime number?
No. 87988 = × 21997, so it is divisible by 2.
What are the factors of 87988?
1, 2, 4, 21997, 43994, 87988.
What is 87988 in binary?
10101011110110100 (hexadecimal 157B4, octal 253664).
What is the square root of 87988?
About 296.6277, exactly 2√21997.
Is 87988 divisible by 3?
No. Its digits add up to 40, which is not a multiple of 3.
What is special about the number 87988?
It is a composite number with 6 divisors.