The number 47987
47987 is a composite number with 4 divisors. Its prime factorisation is 47 × 1021. Divisors (4): 1, 47, 1021, 47987.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 47987: a semiprime: 47 × 1021, the product of two primes.
- 2
47987 is composite. Its prime factorisation is
- 3
The divisors add up to 49056; without 47987 itself that is 1069, so 47987 is deficient (1069 is less than 47987). Euler's totient φ(47987) = 46920 numbers up to 47987 share no factor with it.
- 4
The digits of 47987 add up to 35, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 52 steps to reach 1.
LaTeX source of the formulas on this page
\[ 47987 = 47 \times 1021 \]
47987 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 49056 |
| Euler totient φ(n) | 46920 |
| Square | 2302752169 |
| Cube | 110502168333803 |
| Square root | 219.059353 |
| Digit sum / digital root | 35 / 8 |
| Collatz steps to 1 | 52 |
| Scientific notation | 4.7987 × |
47987 in other forms
| Form | Value |
|---|---|
| In words | forty-seven thousand nine hundred and eighty-seven |
| Binary (base 2) | 1011101101110011 |
| Octal (base 8) | 135563 |
| Hexadecimal (base 16) | BB73 |
| Base 3 | 2102211022 |
| As time | 47987 seconds = 13 h 19 min 47 s |
Is 47987 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | 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 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | 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 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 47987 a prime number?
No. 47987 = 47 × 1021, so it is divisible by 47.
What are the factors of 47987?
1, 47, 1021, 47987.
What is 47987 in binary?
1011101101110011 (hexadecimal BB73, octal 135563).
What is the square root of 47987?
About 219.0594.
Is 47987 divisible by 3?
No. Its digits add up to 35, which is not a multiple of 3.
What is special about the number 47987?
47987 is a semiprime: 47 × 1021, the product of two primes.