The number 388
388 is a composite number with 6 divisors. Its prime factorisation is × 97. Divisors (6): 1, 2, 4, 97, 194, 388.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
388 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
388 is composite. Its prime factorisation is
- 3
The divisors add up to 686; without 388 itself that is 298, so 388 is deficient (298 is less than 388). Euler's totient φ(388) = 192 numbers up to 388 share no factor with it.
- 4
The digits of 388 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 120 steps to reach 1.
LaTeX source of the formulas on this page
\[ 388 = 2^{2} \times 97 \]388 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 686 |
| Euler totient φ(n) | 192 |
| Square | 150544 |
| Cube | 58411072 |
| Square root | 19.697716 (= 2√97) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 120 |
| Scientific notation | 3.88 × |
388 in other forms
| Form | Value |
|---|---|
| In words | three hundred and eighty-eight |
| Roman numerals | CCCLXXXVIII |
| Binary (base 2) | 110000100 |
| Octal (base 8) | 604 |
| Hexadecimal (base 16) | 184 |
| Base 3 | 112101 |
| As time | 388 seconds = 6 min 28 s |
Is 388 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (388 ÷ 2 = 194) | 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 (388 ÷ 4 = 97) | 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 4) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | 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 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 388 a prime number?
No. 388 = × 97, so it is divisible by 2.
What are the factors of 388?
1, 2, 4, 97, 194, 388.
What is 388 in binary?
110000100 (hexadecimal 184, octal 604).
What is the square root of 388?
About 19.6977, exactly 2√97.
What is 388 in Roman numerals?
CCCLXXXVIII.
Is 388 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 388?
It is a composite number with 6 divisors.