The number 1745
1745 is a composite number with 4 divisors. Its prime factorisation is 5 × 349. Divisors (4): 1, 5, 349, 1745.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1745: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 5 × 349, the product of two primes.
- 2
1745 is composite. Its prime factorisation is
- 3
The divisors add up to 2100; without 1745 itself that is 355, so 1745 is deficient (355 is less than 1745). Euler's totient φ(1745) = 1392 numbers up to 1745 share no factor with it.
- 4
The digits of 1745 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 148 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1745 = 5 \times 349 \]
1745 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 2100 |
| Euler totient φ(n) | 1392 |
| Square | 3045025 |
| Cube | 5313568625 |
| Square root | 41.773197 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 148 |
| Scientific notation | 1.745 × |
1745 in other forms
| Form | Value |
|---|---|
| In words | one thousand seven hundred and forty-five |
| Roman numerals | MDCCXLV |
| Binary (base 2) | 11011010001 |
| Octal (base 8) | 3321 |
| Hexadecimal (base 16) | 6D1 |
| Base 3 | 2101122 |
| As time | 1745 seconds = 29 min 5 s |
Is 1745 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 | Yes (1745 ÷ 5 = 349) | 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 | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | 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 7) | 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 1745 a prime number?
No. 1745 = 5 × 349, so it is divisible by 5.
What are the factors of 1745?
1, 5, 349, 1745.
What is 1745 in binary?
11011010001 (hexadecimal 6D1, octal 3321).
What is the square root of 1745?
About 41.7732.
What is 1745 in Roman numerals?
MDCCXLV.
Is 1745 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 1745?
1745 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 5 × 349, the product of two primes.