The number 749
749 is a composite number with 4 divisors. Its prime factorisation is 7 × 107. Divisors (4): 1, 7, 107, 749.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 749: a semiprime: 7 × 107, the product of two primes.
- 2
749 is composite. Its prime factorisation is
- 3
The divisors add up to 864; without 749 itself that is 115, so 749 is deficient (115 is less than 749). Euler's totient φ(749) = 636 numbers up to 749 share no factor with it.
- 4
The digits of 749 add up to 20, 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
\[ 749 = 7 \times 107 \]
749 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 864 |
| Euler totient φ(n) | 636 |
| Square | 561001 |
| Cube | 420189749 |
| Square root | 27.367864 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 46 |
| Scientific notation | 7.49 × |
749 in other forms
| Form | Value |
|---|---|
| In words | seven hundred and forty-nine |
| Roman numerals | DCCXLIX |
| Binary (base 2) | 1011101101 |
| Octal (base 8) | 1355 |
| Hexadecimal (base 16) | 2ED |
| Base 3 | 1000202 |
| As time | 749 seconds = 12 min 29 s |
Is 749 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 2) | 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 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (749 ÷ 7 = 107) | 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 5) | 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 9) | 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 749 a prime number?
No. 749 = 7 × 107, so it is divisible by 7.
What are the factors of 749?
1, 7, 107, 749.
What is 749 in binary?
1011101101 (hexadecimal 2ED, octal 1355).
What is the square root of 749?
About 27.3679.
What is 749 in Roman numerals?
DCCXLIX.
Is 749 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 749?
749 is a semiprime: 7 × 107, the product of two primes.