The number 1278
1278 is a composite number with 12 divisors. Its prime factorisation is 2 × × 71. Divisors (12): 1, 2, 3, 6, 9, 18, 71, 142, 213, 426, 639, 1278.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1278: a Harshad number: divisible by its digit sum 18.
- 2
1278 is composite. Its prime factorisation is
- 3
The divisors add up to 2808; without 1278 itself that is 1530, so 1278 is abundant (1530 is more than 1278). Euler's totient φ(1278) = 420 numbers up to 1278 share no factor with it.
- 4
The digits of 1278 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 132 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1278 = 2 \times 3^{2} \times 71 \]1278 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 2808 |
| Euler totient φ(n) | 420 |
| Square | 1633284 |
| Cube | 2087336952 |
| Square root | 35.749126 (= 3√142) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 132 |
| Scientific notation | 1.278 × |
1278 in other forms
| Form | Value |
|---|---|
| In words | one thousand two hundred and seventy-eight |
| Roman numerals | MCCLXXVIII |
| Binary (base 2) | 10011111110 |
| Octal (base 8) | 2376 |
| Hexadecimal (base 16) | 4FE |
| Base 3 | 1202100 |
| As time | 1278 seconds = 21 min 18 s |
Is 1278 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (1278 ÷ 2 = 639) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (1278 ÷ 3 = 426) | 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 (1278 ÷ 6 = 213) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (1278 ÷ 9 = 142) | 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 1278 a prime number?
No. 1278 = 2 × × 71, so it is divisible by 2.
What are the factors of 1278?
1, 2, 3, 6, 9, 18, 71, 142, 213, 426, 639, 1278.
What is 1278 in binary?
10011111110 (hexadecimal 4FE, octal 2376).
What is the square root of 1278?
About 35.7491, exactly 3√142.
What is 1278 in Roman numerals?
MCCLXXVIII.
Is 1278 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 1278?
1278 is a Harshad number: divisible by its digit sum 18.