The number 1315
1315 is a composite number with 4 divisors. Its prime factorisation is 5 × 263. Divisors (4): 1, 5, 263, 1315.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1315: a semiprime: 5 × 263, the product of two primes.
- 2
1315 is composite. Its prime factorisation is
- 3
The divisors add up to 1584; without 1315 itself that is 269, so 1315 is deficient (269 is less than 1315). Euler's totient φ(1315) = 1048 numbers up to 1315 share no factor with it.
- 4
The digits of 1315 add up to 10, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 52 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1315 = 5 \times 263 \]
1315 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 1584 |
| Euler totient φ(n) | 1048 |
| Square | 1729225 |
| Cube | 2273930875 |
| Square root | 36.262929 |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 52 |
| Scientific notation | 1.315 × |
1315 in other forms
| Form | Value |
|---|---|
| In words | one thousand three hundred and fifteen |
| Roman numerals | MCCCXV |
| Binary (base 2) | 10100100011 |
| Octal (base 8) | 2443 |
| Hexadecimal (base 16) | 523 |
| Base 3 | 1210201 |
| As time | 1315 seconds = 21 min 55 s |
Is 1315 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 (1315 ÷ 5 = 263) | 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 6) | 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 1) | 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 | No (remainder 6) | 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 1315 a prime number?
No. 1315 = 5 × 263, so it is divisible by 5.
What are the factors of 1315?
1, 5, 263, 1315.
What is 1315 in binary?
10100100011 (hexadecimal 523, octal 2443).
What is the square root of 1315?
About 36.2629.
What is 1315 in Roman numerals?
MCCCXV.
Is 1315 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 1315?
1315 is a semiprime: 5 × 263, the product of two primes.