The number 628
628 is a composite number with 6 divisors. Its prime factorisation is × 157. Divisors (6): 1, 2, 4, 157, 314, 628.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
628 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
628 is composite. Its prime factorisation is
- 3
The divisors add up to 1106; without 628 itself that is 478, so 628 is deficient (478 is less than 628). Euler's totient φ(628) = 312 numbers up to 628 share no factor with it.
- 4
The digits of 628 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 38 steps to reach 1.
LaTeX source of the formulas on this page
\[ 628 = 2^{2} \times 157 \]628 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 1106 |
| Euler totient φ(n) | 312 |
| Square | 394384 |
| Cube | 247673152 |
| Square root | 25.059928 (= 2√157) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 38 |
| Scientific notation | 6.28 × |
628 in other forms
| Form | Value |
|---|---|
| In words | six hundred and twenty-eight |
| Roman numerals | DCXXVIII |
| Binary (base 2) | 1001110100 |
| Octal (base 8) | 1164 |
| Hexadecimal (base 16) | 274 |
| Base 3 | 212021 |
| As time | 628 seconds = 10 min 28 s |
Is 628 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (628 ÷ 2 = 314) | 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 (628 ÷ 4 = 157) | 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 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 7) | 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 1) | 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 628 a prime number?
No. 628 = × 157, so it is divisible by 2.
What are the factors of 628?
1, 2, 4, 157, 314, 628.
What is 628 in binary?
1001110100 (hexadecimal 274, octal 1164).
What is the square root of 628?
About 25.0599, exactly 2√157.
What is 628 in Roman numerals?
DCXXVIII.
Is 628 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 628?
It is a composite number with 6 divisors.