The number 3986
3986 is a composite number with 4 divisors. Its prime factorisation is 2 × 1993. Divisors (4): 1, 2, 1993, 3986.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 3986: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 1993, the product of two primes.
- 2
3986 is composite. Its prime factorisation is
- 3
The divisors add up to 5982; without 3986 itself that is 1996, so 3986 is deficient (1996 is less than 3986). Euler's totient φ(3986) = 1992 numbers up to 3986 share no factor with it.
- 4
The digits of 3986 add up to 26, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 51 steps to reach 1.
LaTeX source of the formulas on this page
\[ 3986 = 2 \times 1993 \]
3986 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 5982 |
| Euler totient φ(n) | 1992 |
| Square | 15888196 |
| Cube | 63330349256 |
| Square root | 63.134776 |
| Digit sum / digital root | 26 / 8 |
| Collatz steps to 1 | 51 |
| Scientific notation | 3.986 × |
3986 in other forms
| Form | Value |
|---|---|
| In words | three thousand nine hundred and eighty-six |
| Roman numerals | MMMCMLXXXVI |
| Binary (base 2) | 111110010010 |
| Octal (base 8) | 7622 |
| Hexadecimal (base 16) | F92 |
| Base 3 | 12110122 |
| As time | 3986 seconds = 1 h 6 min 26 s |
Is 3986 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (3986 ÷ 2 = 1993) | 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 1) | 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 3) | 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 6) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | 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 3986 a prime number?
No. 3986 = 2 × 1993, so it is divisible by 2.
What are the factors of 3986?
1, 2, 1993, 3986.
What is 3986 in binary?
111110010010 (hexadecimal F92, octal 7622).
What is the square root of 3986?
About 63.1348.
What is 3986 in Roman numerals?
MMMCMLXXXVI.
Is 3986 divisible by 3?
No. Its digits add up to 26, which is not a multiple of 3.
What is special about the number 3986?
3986 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 1993, the product of two primes.