The number 7220
7220 is a composite number with 18 divisors. Its prime factorisation is × 5 × . Divisors (18): 1, 2, 4, 5, 10, 19, 20, 38, 76, 95, 190, 361, 380, 722, 1444, 1805 … 7220.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
7220 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
7220 is composite. Its prime factorisation is
- 3
The divisors add up to 16002; without 7220 itself that is 8782, so 7220 is abundant (8782 is more than 7220). Euler's totient φ(7220) = 2736 numbers up to 7220 share no factor with it.
- 4
The digits of 7220 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 57 steps to reach 1.
LaTeX source of the formulas on this page
\[ 7220 = 2^{2} \times 5 \times 19^{2} \]7220 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 18 |
| Sum of divisors | 16002 |
| Euler totient φ(n) | 2736 |
| Square | 52128400 |
| Cube | 376367048000 |
| Square root | 84.970583 (= 38√5) |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 57 |
| Scientific notation | 7.22 × |
7220 in other forms
| Form | Value |
|---|---|
| In words | seven thousand two hundred and twenty |
| Binary (base 2) | 1110000110100 |
| Octal (base 8) | 16064 |
| Hexadecimal (base 16) | 1C34 |
| Base 3 | 100220102 |
| As time | 7220 seconds = 2 h 0 min 20 s |
Is 7220 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (7220 ÷ 2 = 3610) | 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 (7220 ÷ 4 = 1805) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (7220 ÷ 5 = 1444) | 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 4) | 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 (7220 ÷ 10 = 722) | 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 7220 a prime number?
No. 7220 = × 5 × , so it is divisible by 2.
What are the factors of 7220?
1, 2, 4, 5, 10, 19, 20, 38, 76, 95, 190, 361, 380, 722, 1444, 1805, 3610, 7220.
What is 7220 in binary?
1110000110100 (hexadecimal 1C34, octal 16064).
What is the square root of 7220?
About 84.9706, exactly 38√5.
Is 7220 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 7220?
It is a composite number with 18 divisors.