The number 878
878 is a palindrome: it reads 878 backwards too. Its prime factorisation is 2 × 439. Divisors (4): 1, 2, 439, 878.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 878: a palindrome: it reads 878 backwards too; a semiprime: 2 × 439, the product of two primes.
- 2
878 is composite. Its prime factorisation is
- 3
The divisors add up to 1320; without 878 itself that is 442, so 878 is deficient (442 is less than 878). Euler's totient φ(878) = 438 numbers up to 878 share no factor with it.
- 4
The digits of 878 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 54 steps to reach 1.
LaTeX source of the formulas on this page
\[ 878 = 2 \times 439 \]
878 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 1320 |
| Euler totient φ(n) | 438 |
| Square | 770884 |
| Cube | 676836152 |
| Square root | 29.631065 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 54 |
| Scientific notation | 8.78 × |
878 in other forms
| Form | Value |
|---|---|
| In words | eight hundred and seventy-eight |
| Roman numerals | DCCCLXXVIII |
| Binary (base 2) | 1101101110 |
| Octal (base 8) | 1556 |
| Hexadecimal (base 16) | 36E |
| Base 3 | 1012112 |
| As time | 878 seconds = 14 min 38 s |
Is 878 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (878 ÷ 2 = 439) | 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 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 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 | No (remainder 5) | 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 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 878 a prime number?
No. 878 = 2 × 439, so it is divisible by 2.
What are the factors of 878?
1, 2, 439, 878.
What is 878 in binary?
1101101110 (hexadecimal 36E, octal 1556).
What is the square root of 878?
About 29.6311.
What is 878 in Roman numerals?
DCCCLXXVIII.
Is 878 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 878?
878 is a palindrome: it reads 878 backwards too; a semiprime: 2 × 439, the product of two primes.