The number 10221
10221 is a composite number with 4 divisors. Its prime factorisation is 3 × 3407. Divisors (4): 1, 3, 3407, 10221.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 10221: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 3 × 3407, the product of two primes.
- 2
10221 is composite. Its prime factorisation is
- 3
The divisors add up to 13632; without 10221 itself that is 3411, so 10221 is deficient (3411 is less than 10221). Euler's totient φ(10221) = 6812 numbers up to 10221 share no factor with it.
- 4
The digits of 10221 add up to 6, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 60 steps to reach 1.
LaTeX source of the formulas on this page
\[ 10221 = 3 \times 3407 \]
10221 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 13632 |
| Euler totient φ(n) | 6812 |
| Square | 104468841 |
| Cube | 1067776023861 |
| Square root | 101.098961 |
| Digit sum / digital root | 6 / 6 |
| Collatz steps to 1 | 60 |
| Scientific notation | 1.0221 × |
10221 in other forms
| Form | Value |
|---|---|
| In words | ten thousand two hundred and twenty-one |
| Binary (base 2) | 10011111101101 |
| Octal (base 8) | 23755 |
| Hexadecimal (base 16) | 27ED |
| Base 3 | 112000120 |
| As time | 10221 seconds = 2 h 50 min 21 s |
Is 10221 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 (10221 ÷ 3 = 3407) | 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 | 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 | No (remainder 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | 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 2) | 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 10221 a prime number?
No. 10221 = 3 × 3407, so it is divisible by 3.
What are the factors of 10221?
1, 3, 3407, 10221.
What is 10221 in binary?
10011111101101 (hexadecimal 27ED, octal 23755).
What is the square root of 10221?
About 101.0990.
Is 10221 divisible by 3?
Yes. Its digits add up to 6, a multiple of 3.
What is special about the number 10221?
10221 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 3 × 3407, the product of two primes.