The number 16421
16421 is the 1903rd prime number. Its only divisors are 1 and 16421.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 16421: the 1903rd prime number.
- 2
16421 is prime, so its only factors are 1 and 16421. It is the 1903rd prime; the next prime is 16427 and the one before is 16417.
- 3
The divisors add up to 16422; without 16421 itself that is 1, so 16421 is deficient (1 is less than 16421). Euler's totient φ(16421) = 16420 numbers up to 16421 share no factor with it.
- 4
The digits of 16421 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 159 steps to reach 1.
16421 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 16422 |
| Euler totient φ(n) | 16420 |
| Square | 269649241 |
| Cube | 4427910186461 |
| Square root | 128.144450 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 159 |
| Scientific notation | 1.6421 × |
16421 in other forms
| Form | Value |
|---|---|
| In words | sixteen thousand four hundred and twenty-one |
| Binary (base 2) | 100000000100101 |
| Octal (base 8) | 40045 |
| Hexadecimal (base 16) | 4025 |
| Base 3 | 211112012 |
| As time | 16421 seconds = 4 h 33 min 41 s |
Is 16421 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 | No (remainder 2) | 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 5) | 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 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 16421 a prime number?
Yes. 16421 is divisible only by 1 and itself.
What are the factors of 16421?
1, 16421.
What is 16421 in binary?
100000000100101 (hexadecimal 4025, octal 40045).
What is the square root of 16421?
About 128.1444.
Is 16421 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 16421?
16421 is the 1903rd prime number.