The number 624
624 is a composite number with 20 divisors. Its prime factorisation is × 3 × 13. Divisors (20): 1, 2, 3, 4, 6, 8, 12, 13, 16, 24, 26, 39, 48, 52, 78, 104 … 624.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 624: a Harshad number: divisible by its digit sum 12.
- 2
624 is composite. Its prime factorisation is
- 3
The divisors add up to 1736; without 624 itself that is 1112, so 624 is abundant (1112 is more than 624). Euler's totient φ(624) = 192 numbers up to 624 share no factor with it.
- 4
The digits of 624 add up to 12, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 38 steps to reach 1.
LaTeX source of the formulas on this page
\[ 624 = 2^{4} \times 3 \times 13 \]624 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 20 |
| Sum of divisors | 1736 |
| Euler totient φ(n) | 192 |
| Square | 389376 |
| Cube | 242970624 |
| Square root | 24.979992 (= 4√39) |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 38 |
| Scientific notation | 6.24 × |
624 in other forms
| Form | Value |
|---|---|
| In words | six hundred and twenty-four |
| Roman numerals | DCXXIV |
| Binary (base 2) | 1001110000 |
| Octal (base 8) | 1160 |
| Hexadecimal (base 16) | 270 |
| Base 3 | 212010 |
| As time | 624 seconds = 10 min 24 s |
Is 624 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (624 ÷ 2 = 312) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (624 ÷ 3 = 208) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (624 ÷ 4 = 156) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (624 ÷ 6 = 104) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 | Yes (624 ÷ 8 = 78) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 4) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (624 ÷ 12 = 52) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 624 a prime number?
No. 624 = × 3 × 13, so it is divisible by 2.
What are the factors of 624?
1, 2, 3, 4, 6, 8, 12, 13, 16, 24, 26, 39, 48, 52, 78, 104, 156, 208, 312, 624.
What is 624 in binary?
1001110000 (hexadecimal 270, octal 1160).
What is the square root of 624?
About 24.9800, exactly 4√39.
What is 624 in Roman numerals?
DCXXIV.
Is 624 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 624?
624 is a Harshad number: divisible by its digit sum 12.