The number 3940
3940 is a composite number with 12 divisors. Its prime factorisation is × 5 × 197. Divisors (12): 1, 2, 4, 5, 10, 20, 197, 394, 788, 985, 1970, 3940.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
3940 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
3940 is composite. Its prime factorisation is
- 3
The divisors add up to 8316; without 3940 itself that is 4376, so 3940 is abundant (4376 is more than 3940). Euler's totient φ(3940) = 1568 numbers up to 3940 share no factor with it.
- 4
The digits of 3940 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 25 steps to reach 1.
LaTeX source of the formulas on this page
\[ 3940 = 2^{2} \times 5 \times 197 \]3940 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 8316 |
| Euler totient φ(n) | 1568 |
| Square | 15523600 |
| Cube | 61162984000 |
| Square root | 62.769419 (= 2√985) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 25 |
| Scientific notation | 3.94 × |
3940 in other forms
| Form | Value |
|---|---|
| In words | three thousand nine hundred and forty |
| Roman numerals | MMMCMXL |
| Binary (base 2) | 111101100100 |
| Octal (base 8) | 7544 |
| Hexadecimal (base 16) | F64 |
| Base 3 | 12101221 |
| As time | 3940 seconds = 1 h 5 min 40 s |
Is 3940 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (3940 ÷ 2 = 1970) | 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 (3940 ÷ 4 = 985) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (3940 ÷ 5 = 788) | 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 6) | 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 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (3940 ÷ 10 = 394) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | 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 3940 a prime number?
No. 3940 = × 5 × 197, so it is divisible by 2.
What are the factors of 3940?
1, 2, 4, 5, 10, 20, 197, 394, 788, 985, 1970, 3940.
What is 3940 in binary?
111101100100 (hexadecimal F64, octal 7544).
What is the square root of 3940?
About 62.7694, exactly 2√985.
What is 3940 in Roman numerals?
MMMCMXL.
Is 3940 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 3940?
It is a composite number with 12 divisors.