The number 1618
1618 is a composite number with 4 divisors. Its prime factorisation is 2 × 809. Divisors (4): 1, 2, 809, 1618.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1618: a semiprime: 2 × 809, the product of two primes.
- 2
1618 is composite. Its prime factorisation is
- 3
The divisors add up to 2430; without 1618 itself that is 812, so 1618 is deficient (812 is less than 1618). Euler's totient φ(1618) = 808 numbers up to 1618 share no factor with it.
- 4
The digits of 1618 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 47 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1618 = 2 \times 809 \]
1618 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 2430 |
| Euler totient φ(n) | 808 |
| Square | 2617924 |
| Cube | 4235801032 |
| Square root | 40.224371 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 47 |
| Scientific notation | 1.618 × |
1618 in other forms
| Form | Value |
|---|---|
| In words | one thousand six hundred and eighteen |
| Roman numerals | MDCXVIII |
| Binary (base 2) | 11001010010 |
| Octal (base 8) | 3122 |
| Hexadecimal (base 16) | 652 |
| Base 3 | 2012221 |
| As time | 1618 seconds = 26 min 58 s |
Is 1618 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (1618 ÷ 2 = 809) | 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 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | 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 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | 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 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1618 a prime number?
No. 1618 = 2 × 809, so it is divisible by 2.
What are the factors of 1618?
1, 2, 809, 1618.
What is 1618 in binary?
11001010010 (hexadecimal 652, octal 3122).
What is the square root of 1618?
About 40.2244.
What is 1618 in Roman numerals?
MDCXVIII.
Is 1618 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 1618?
1618 is a semiprime: 2 × 809, the product of two primes.