The number 625
625 is a perfect power () and a perfect square (25²). Its prime factorisation is . Divisors (5): 1, 5, 25, 125, 625.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 625: a perfect power (); a perfect square (25²).
- 2
625 is composite. Its prime factorisation is
- 3
The divisors add up to 781; without 625 itself that is 156, so 625 is deficient (156 is less than 625). Euler's totient φ(625) = 500 numbers up to 625 share no factor with it.
- 4
The digits of 625 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 25 steps to reach 1.
LaTeX source of the formulas on this page
\[ 625 = 5^{4} \]625 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 5 |
| Sum of divisors | 781 |
| Euler totient φ(n) | 500 |
| Square | 390625 |
| Cube | 244140625 |
| Square root | 25 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 25 |
| Scientific notation | 6.25 × |
| Perfect power |
625 in other forms
| Form | Value |
|---|---|
| In words | six hundred and twenty-five |
| Roman numerals | DCXXV |
| Binary (base 2) | 1001110001 |
| Octal (base 8) | 1161 |
| Hexadecimal (base 16) | 271 |
| Base 3 | 212011 |
| As time | 625 seconds = 10 min 25 s |
Is 625 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | 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 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (625 ÷ 5 = 125) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 1) | 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 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 625 a prime number?
No. 625 = , so it is divisible by 5.
What are the factors of 625?
1, 5, 25, 125, 625.
What is 625 in binary?
1001110001 (hexadecimal 271, octal 1161).
What is the square root of 625?
25, because 25 × 25 = 625.
What is 625 in Roman numerals?
DCXXV.
Is 625 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 625?
625 is a perfect power (); a perfect square (25²).