The number 7120
7120 is a composite number with 20 divisors. Its prime factorisation is × 5 × 89. Divisors (20): 1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 89, 178, 356, 445, 712, 890 … 7120.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 7120: a Harshad number: divisible by its digit sum 10.
- 2
7120 is composite. Its prime factorisation is
- 3
The divisors add up to 16740; without 7120 itself that is 9620, so 7120 is abundant (9620 is more than 7120). Euler's totient φ(7120) = 2816 numbers up to 7120 share no factor with it.
- 4
The digits of 7120 add up to 10, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 75 steps to reach 1.
LaTeX source of the formulas on this page
\[ 7120 = 2^{4} \times 5 \times 89 \]7120 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 20 |
| Sum of divisors | 16740 |
| Euler totient φ(n) | 2816 |
| Square | 50694400 |
| Cube | 360944128000 |
| Square root | 84.380092 (= 4√445) |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 75 |
| Scientific notation | 7.12 × |
7120 in other forms
| Form | Value |
|---|---|
| In words | seven thousand one hundred and twenty |
| Binary (base 2) | 1101111010000 |
| Octal (base 8) | 15720 |
| Hexadecimal (base 16) | 1BD0 |
| Base 3 | 100202201 |
| As time | 7120 seconds = 1 h 58 min 40 s |
Is 7120 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (7120 ÷ 2 = 3560) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (7120 ÷ 4 = 1780) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (7120 ÷ 5 = 1424) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 (7120 ÷ 8 = 890) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (7120 ÷ 10 = 712) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 7120 a prime number?
No. 7120 = × 5 × 89, so it is divisible by 2.
What are the factors of 7120?
1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 89, 178, 356, 445, 712, 890, 1424, 1780, 3560, 7120.
What is 7120 in binary?
1101111010000 (hexadecimal 1BD0, octal 15720).
What is the square root of 7120?
About 84.3801, exactly 4√445.
Is 7120 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 7120?
7120 is a Harshad number: divisible by its digit sum 10.