The number 7880
7880 is a composite number with 16 divisors. Its prime factorisation is × 5 × 197. Divisors (16): 1, 2, 4, 5, 8, 10, 20, 40, 197, 394, 788, 985, 1576, 1970, 3940, 7880.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
7880 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
7880 is composite. Its prime factorisation is
- 3
The divisors add up to 17820; without 7880 itself that is 9940, so 7880 is abundant (9940 is more than 7880). Euler's totient φ(7880) = 3136 numbers up to 7880 share no factor with it.
- 4
The digits of 7880 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 26 steps to reach 1.
LaTeX source of the formulas on this page
\[ 7880 = 2^{3} \times 5 \times 197 \]7880 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 17820 |
| Euler totient φ(n) | 3136 |
| Square | 62094400 |
| Cube | 489303872000 |
| Square root | 88.769364 (= 2√1970) |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 26 |
| Scientific notation | 7.88 × |
7880 in other forms
| Form | Value |
|---|---|
| In words | seven thousand eight hundred and eighty |
| Binary (base 2) | 1111011001000 |
| Octal (base 8) | 17310 |
| Hexadecimal (base 16) | 1EC8 |
| Base 3 | 101210212 |
| As time | 7880 seconds = 2 h 11 min 20 s |
Is 7880 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (7880 ÷ 2 = 3940) | 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 | Yes (7880 ÷ 4 = 1970) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (7880 ÷ 5 = 1576) | 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 5) | 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 | Yes (7880 ÷ 8 = 985) | 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 | Yes (7880 ÷ 10 = 788) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 7880 a prime number?
No. 7880 = × 5 × 197, so it is divisible by 2.
What are the factors of 7880?
1, 2, 4, 5, 8, 10, 20, 40, 197, 394, 788, 985, 1576, 1970, 3940, 7880.
What is 7880 in binary?
1111011001000 (hexadecimal 1EC8, octal 17310).
What is the square root of 7880?
About 88.7694, exactly 2√1970.
Is 7880 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 7880?
It is a composite number with 16 divisors.