The number 8120
8120 is a composite number with 32 divisors. Its prime factorisation is × 5 × 7 × 29. Divisors (32): 1, 2, 4, 5, 7, 8, 10, 14, 20, 28, 29, 35, 40, 56, 58, 70 … 8120.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
8120 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
8120 is composite. Its prime factorisation is
- 3
The divisors add up to 21600; without 8120 itself that is 13480, so 8120 is abundant (13480 is more than 8120). Euler's totient φ(8120) = 2688 numbers up to 8120 share no factor with it.
- 4
The digits of 8120 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 39 steps to reach 1.
LaTeX source of the formulas on this page
\[ 8120 = 2^{3} \times 5 \times 7 \times 29 \]8120 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 21600 |
| Euler totient φ(n) | 2688 |
| Square | 65934400 |
| Cube | 535387328000 |
| Square root | 90.111043 (= 2√2030) |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 39 |
| Scientific notation | 8.12 × |
8120 in other forms
| Form | Value |
|---|---|
| In words | eight thousand one hundred and twenty |
| Binary (base 2) | 1111110111000 |
| Octal (base 8) | 17670 |
| Hexadecimal (base 16) | 1FB8 |
| Base 3 | 102010202 |
| As time | 8120 seconds = 2 h 15 min 20 s |
Is 8120 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (8120 ÷ 2 = 4060) | 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 (8120 ÷ 4 = 2030) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (8120 ÷ 5 = 1624) | 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 | Yes (8120 ÷ 7 = 1160) | 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 (8120 ÷ 8 = 1015) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (8120 ÷ 10 = 812) | 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 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 8120 a prime number?
No. 8120 = × 5 × 7 × 29, so it is divisible by 2.
What are the factors of 8120?
1, 2, 4, 5, 7, 8, 10, 14, 20, 28, 29, 35, 40, 56, 58, 70, 116, 140, 145, 203, 232, 280, 290, 406, 580, 812, 1015, 1160, 1624, 2030, 4060, 8120.
What is 8120 in binary?
1111110111000 (hexadecimal 1FB8, octal 17670).
What is the square root of 8120?
About 90.1110, exactly 2√2030.
Is 8120 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 8120?
It is a composite number with 32 divisors.