The number 723
723 is a composite number with 4 divisors. Its prime factorisation is 3 × 241. Divisors (4): 1, 3, 241, 723.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 723: a semiprime: 3 × 241, the product of two primes.
- 2
723 is composite. Its prime factorisation is
- 3
The divisors add up to 968; without 723 itself that is 245, so 723 is deficient (245 is less than 723). Euler's totient φ(723) = 480 numbers up to 723 share no factor with it.
- 4
The digits of 723 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 46 steps to reach 1.
LaTeX source of the formulas on this page
\[ 723 = 3 \times 241 \]
723 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 968 |
| Euler totient φ(n) | 480 |
| Square | 522729 |
| Cube | 377933067 |
| Square root | 26.888659 |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 46 |
| Scientific notation | 7.23 × |
723 in other forms
| Form | Value |
|---|---|
| In words | seven hundred and twenty-three |
| Roman numerals | DCCXXIII |
| Binary (base 2) | 1011010011 |
| Octal (base 8) | 1323 |
| Hexadecimal (base 16) | 2D3 |
| Base 3 | 222210 |
| As time | 723 seconds = 12 min 3 s |
Is 723 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 | Yes (723 ÷ 3 = 241) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | 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 3) | 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 3) | 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 3) | 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 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 723 a prime number?
No. 723 = 3 × 241, so it is divisible by 3.
What are the factors of 723?
1, 3, 241, 723.
What is 723 in binary?
1011010011 (hexadecimal 2D3, octal 1323).
What is the square root of 723?
About 26.8887.
What is 723 in Roman numerals?
DCCXXIII.
Is 723 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 723?
723 is a semiprime: 3 × 241, the product of two primes.