The number 3820
3820 is a composite number with 12 divisors. Its prime factorisation is × 5 × 191. Divisors (12): 1, 2, 4, 5, 10, 20, 191, 382, 764, 955, 1910, 3820.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
3820 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
3820 is composite. Its prime factorisation is
- 3
The divisors add up to 8064; without 3820 itself that is 4244, so 3820 is abundant (4244 is more than 3820). Euler's totient φ(3820) = 1520 numbers up to 3820 share no factor with it.
- 4
The digits of 3820 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 30 steps to reach 1.
LaTeX source of the formulas on this page
\[ 3820 = 2^{2} \times 5 \times 191 \]3820 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 8064 |
| Euler totient φ(n) | 1520 |
| Square | 14592400 |
| Cube | 55742968000 |
| Square root | 61.806149 (= 2√955) |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 30 |
| Scientific notation | 3.82 × |
3820 in other forms
| Form | Value |
|---|---|
| In words | three thousand eight hundred and twenty |
| Roman numerals | MMMDCCCXX |
| Binary (base 2) | 111011101100 |
| Octal (base 8) | 7354 |
| Hexadecimal (base 16) | EEC |
| Base 3 | 12020111 |
| As time | 3820 seconds = 1 h 3 min 40 s |
Is 3820 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (3820 ÷ 2 = 1910) | 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 (3820 ÷ 4 = 955) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (3820 ÷ 5 = 764) | 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 | Yes (3820 ÷ 10 = 382) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | 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 3820 a prime number?
No. 3820 = × 5 × 191, so it is divisible by 2.
What are the factors of 3820?
1, 2, 4, 5, 10, 20, 191, 382, 764, 955, 1910, 3820.
What is 3820 in binary?
111011101100 (hexadecimal EEC, octal 7354).
What is the square root of 3820?
About 61.8061, exactly 2√955.
What is 3820 in Roman numerals?
MMMDCCCXX.
Is 3820 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 3820?
It is a composite number with 12 divisors.