The number 47978
47978 is a composite number with 16 divisors. Its prime factorisation is 2 × 7 × 23 × 149. Divisors (16): 1, 2, 7, 14, 23, 46, 149, 161, 298, 322, 1043, 2086, 3427, 6854, 23989, 47978.
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How to work it out
- 1
47978 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
47978 is composite. Its prime factorisation is
- 3
The divisors add up to 86400; without 47978 itself that is 38422, so 47978 is deficient (38422 is less than 47978). Euler's totient φ(47978) = 19536 numbers up to 47978 share no factor with it.
- 4
The digits of 47978 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
\[ 47978 = 2 \times 7 \times 23 \times 149 \]
47978 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 86400 |
| Euler totient φ(n) | 19536 |
| Square | 2301888484 |
| Cube | 110440005685352 |
| Square root | 219.038809 |
| Digit sum / digital root | 35 / 8 |
| Collatz steps to 1 | 52 |
| Scientific notation | 4.7978 × |
47978 in other forms
| Form | Value |
|---|---|
| In words | forty-seven thousand nine hundred and seventy-eight |
| Binary (base 2) | 1011101101101010 |
| Octal (base 8) | 135552 |
| Hexadecimal (base 16) | BB6A |
| Base 3 | 2102210222 |
| As time | 47978 seconds = 13 h 19 min 38 s |
Is 47978 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (47978 ÷ 2 = 23989) | 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 | 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 | Yes (47978 ÷ 7 = 6854) | 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 8) | 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 7) | 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 47978 a prime number?
No. 47978 = 2 × 7 × 23 × 149, so it is divisible by 2.
What are the factors of 47978?
1, 2, 7, 14, 23, 46, 149, 161, 298, 322, 1043, 2086, 3427, 6854, 23989, 47978.
What is 47978 in binary?
1011101101101010 (hexadecimal BB6A, octal 135552).
What is the square root of 47978?
About 219.0388.
Is 47978 divisible by 3?
No. Its digits add up to 35, which is not a multiple of 3.
What is special about the number 47978?
It is a composite number with 16 divisors.