The number 4221
4221 is a composite number with 12 divisors. Its prime factorisation is × 7 × 67. Divisors (12): 1, 3, 7, 9, 21, 63, 67, 201, 469, 603, 1407, 4221.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 4221: a Harshad number: divisible by its digit sum 9.
- 2
4221 is composite. Its prime factorisation is
- 3
The divisors add up to 7072; without 4221 itself that is 2851, so 4221 is deficient (2851 is less than 4221). Euler's totient φ(4221) = 2376 numbers up to 4221 share no factor with it.
- 4
The digits of 4221 add up to 9, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 170 steps to reach 1.
LaTeX source of the formulas on this page
\[ 4221 = 3^{2} \times 7 \times 67 \]4221 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 7072 |
| Euler totient φ(n) | 2376 |
| Square | 17816841 |
| Cube | 75204885861 |
| Square root | 64.969223 (= 3√469) |
| Digit sum / digital root | 9 / 9 |
| Collatz steps to 1 | 170 |
| Scientific notation | 4.221 × |
4221 in other forms
| Form | Value |
|---|---|
| In words | four thousand two hundred and twenty-one |
| Binary (base 2) | 1000001111101 |
| Octal (base 8) | 10175 |
| Hexadecimal (base 16) | 107D |
| Base 3 | 12210100 |
| As time | 4221 seconds = 1 h 10 min 21 s |
Is 4221 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (4221 ÷ 3 = 1407) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (4221 ÷ 7 = 603) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (4221 ÷ 9 = 469) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 4221 a prime number?
No. 4221 = × 7 × 67, so it is divisible by 3.
What are the factors of 4221?
1, 3, 7, 9, 21, 63, 67, 201, 469, 603, 1407, 4221.
What is 4221 in binary?
1000001111101 (hexadecimal 107D, octal 10175).
What is the square root of 4221?
About 64.9692, exactly 3√469.
Is 4221 divisible by 3?
Yes. Its digits add up to 9, a multiple of 3.
What is special about the number 4221?
4221 is a Harshad number: divisible by its digit sum 9.