The number 722
722 is a composite number with 6 divisors. Its prime factorisation is 2 Ć . Divisors (6): 1, 2, 19, 38, 361, 722.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
722 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
722 is composite. Its prime factorisation is
- 3
The divisors add up to 1143; without 722 itself that is 421, so 722 is deficient (421 is less than 722). Euler's totient Ļ(722) = 342 numbers up to 722 share no factor with it.
- 4
The digits of 722 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 46 steps to reach 1.
LaTeX source of the formulas on this page
\[ 722 = 2 \times 19^{2} \]722 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 1143 |
| Euler totient Ļ(n) | 342 |
| Square | 521284 |
| Cube | 376367048 |
| Square root | 26.870058 (= 19ā2) |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 46 |
| Scientific notation | 7.22 Ć |
722 in other forms
| Form | Value |
|---|---|
| In words | seven hundred and twenty-two |
| Roman numerals | DCCXXII |
| Binary (base 2) | 1011010010 |
| Octal (base 8) | 1322 |
| Hexadecimal (base 16) | 2D2 |
| Base 3 | 222202 |
| As time | 722 seconds = 12 min 2 s |
Is 722 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (722 Ć· 2 = 361) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | 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 | No (remainder 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 722 a prime number?
No. 722 = 2 Ć , so it is divisible by 2.
What are the factors of 722?
1, 2, 19, 38, 361, 722.
What is 722 in binary?
1011010010 (hexadecimal 2D2, octal 1322).
What is the square root of 722?
About 26.8701, exactly 19ā2.
What is 722 in Roman numerals?
DCCXXII.
Is 722 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 722?
It is a composite number with 6 divisors.