The number 3890
3890 is a composite number with 8 divisors. Its prime factorisation is 2 × 5 × 389. Divisors (8): 1, 2, 5, 10, 389, 778, 1945, 3890.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
3890 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
3890 is composite. Its prime factorisation is
- 3
The divisors add up to 7020; without 3890 itself that is 3130, so 3890 is deficient (3130 is less than 3890). Euler's totient φ(3890) = 1552 numbers up to 3890 share no factor with it.
- 4
The digits of 3890 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 38 steps to reach 1.
LaTeX source of the formulas on this page
\[ 3890 = 2 \times 5 \times 389 \]
3890 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 7020 |
| Euler totient φ(n) | 1552 |
| Square | 15132100 |
| Cube | 58863869000 |
| Square root | 62.369865 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 38 |
| Scientific notation | 3.89 × |
3890 in other forms
| Form | Value |
|---|---|
| In words | three thousand eight hundred and ninety |
| Roman numerals | MMMDCCCXC |
| Binary (base 2) | 111100110010 |
| Octal (base 8) | 7462 |
| Hexadecimal (base 16) | F32 |
| Base 3 | 12100002 |
| As time | 3890 seconds = 1 h 4 min 50 s |
Is 3890 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (3890 ÷ 2 = 1945) | 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 (3890 ÷ 5 = 778) | 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 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (3890 ÷ 10 = 389) | 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 3890 a prime number?
No. 3890 = 2 × 5 × 389, so it is divisible by 2.
What are the factors of 3890?
1, 2, 5, 10, 389, 778, 1945, 3890.
What is 3890 in binary?
111100110010 (hexadecimal F32, octal 7462).
What is the square root of 3890?
About 62.3699.
What is 3890 in Roman numerals?
MMMDCCCXC.
Is 3890 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 3890?
It is a composite number with 8 divisors.