The number 715
715 is a composite number with 8 divisors. Its prime factorisation is 5 × 11 × 13. Divisors (8): 1, 5, 11, 13, 55, 65, 143, 715.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 715: a Harshad number: divisible by its digit sum 13.
- 2
715 is composite. Its prime factorisation is
- 3
The divisors add up to 1008; without 715 itself that is 293, so 715 is deficient (293 is less than 715). Euler's totient φ(715) = 480 numbers up to 715 share no factor with it.
- 4
The digits of 715 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
\[ 715 = 5 \times 11 \times 13 \]
715 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 1008 |
| Euler totient φ(n) | 480 |
| Square | 511225 |
| Cube | 365525875 |
| Square root | 26.739484 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 25 |
| Scientific notation | 7.15 × |
715 in other forms
| Form | Value |
|---|---|
| In words | seven hundred and fifteen |
| Roman numerals | DCCXV |
| Binary (base 2) | 1011001011 |
| Octal (base 8) | 1313 |
| Hexadecimal (base 16) | 2CB |
| Base 3 | 222111 |
| As time | 715 seconds = 11 min 55 s |
Is 715 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 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (715 ÷ 5 = 143) | 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 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 3) | 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 | Yes (715 ÷ 11 = 65) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 715 a prime number?
No. 715 = 5 × 11 × 13, so it is divisible by 5.
What are the factors of 715?
1, 5, 11, 13, 55, 65, 143, 715.
What is 715 in binary?
1011001011 (hexadecimal 2CB, octal 1313).
What is the square root of 715?
About 26.7395.
What is 715 in Roman numerals?
DCCXV.
Is 715 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 715?
715 is a Harshad number: divisible by its digit sum 13.