The number 13818
13818 is a composite number with 24 divisors. Its prime factorisation is 2 × 3 × × 47. Divisors (24): 1, 2, 3, 6, 7, 14, 21, 42, 47, 49, 94, 98, 141, 147, 282, 294 … 13818.
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How to work it out
- 1
What is special about 13818: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 21.
- 2
13818 is composite. Its prime factorisation is
- 3
The divisors add up to 32832; without 13818 itself that is 19014, so 13818 is abundant (19014 is more than 13818). Euler's totient φ(13818) = 3864 numbers up to 13818 share no factor with it.
- 4
The digits of 13818 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 58 steps to reach 1.
LaTeX source of the formulas on this page
\[ 13818 = 2 \times 3 \times 7^{2} \times 47 \]13818 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 32832 |
| Euler totient φ(n) | 3864 |
| Square | 190937124 |
| Cube | 2638369179432 |
| Square root | 117.549989 (= 7√282) |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 58 |
| Scientific notation | 1.3818 × |
13818 in other forms
| Form | Value |
|---|---|
| In words | thirteen thousand eight hundred and eighteen |
| Binary (base 2) | 11010111111010 |
| Octal (base 8) | 32772 |
| Hexadecimal (base 16) | 35FA |
| Base 3 | 200221210 |
| As time | 13818 seconds = 3 h 50 min 18 s |
Is 13818 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (13818 ÷ 2 = 6909) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (13818 ÷ 3 = 4606) | 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 | Yes (13818 ÷ 6 = 2303) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (13818 ÷ 7 = 1974) | 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 3) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 13818 a prime number?
No. 13818 = 2 × 3 × × 47, so it is divisible by 2.
What are the factors of 13818?
1, 2, 3, 6, 7, 14, 21, 42, 47, 49, 94, 98, 141, 147, 282, 294, 329, 658, 987, 1974, 2303, 4606, 6909, 13818.
What is 13818 in binary?
11010111111010 (hexadecimal 35FA, octal 32772).
What is the square root of 13818?
About 117.5500, exactly 7√282.
Is 13818 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 13818?
13818 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 21.