The number 16401
16401 is a composite number with 16 divisors. Its prime factorisation is 3 × 7 × 11 × 71. Divisors (16): 1, 3, 7, 11, 21, 33, 71, 77, 213, 231, 497, 781, 1491, 2343, 5467, 16401.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
16401 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
16401 is composite. Its prime factorisation is
- 3
The divisors add up to 27648; without 16401 itself that is 11247, so 16401 is deficient (11247 is less than 16401). Euler's totient φ(16401) = 8400 numbers up to 16401 share no factor with it.
- 4
The digits of 16401 add up to 12, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 159 steps to reach 1.
LaTeX source of the formulas on this page
\[ 16401 = 3 \times 7 \times 11 \times 71 \]
16401 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 27648 |
| Euler totient φ(n) | 8400 |
| Square | 268992801 |
| Cube | 4411750929201 |
| Square root | 128.066389 |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 159 |
| Scientific notation | 1.6401 × |
16401 in other forms
| Form | Value |
|---|---|
| In words | sixteen thousand four hundred and one |
| Binary (base 2) | 100000000010001 |
| Octal (base 8) | 40021 |
| Hexadecimal (base 16) | 4011 |
| Base 3 | 211111110 |
| As time | 16401 seconds = 4 h 33 min 21 s |
Is 16401 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 (16401 ÷ 3 = 5467) | 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 (16401 ÷ 7 = 2343) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | 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 | Yes (16401 ÷ 11 = 1491) | 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 16401 a prime number?
No. 16401 = 3 × 7 × 11 × 71, so it is divisible by 3.
What are the factors of 16401?
1, 3, 7, 11, 21, 33, 71, 77, 213, 231, 497, 781, 1491, 2343, 5467, 16401.
What is 16401 in binary?
100000000010001 (hexadecimal 4011, octal 40021).
What is the square root of 16401?
About 128.0664.
Is 16401 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 16401?
It is a composite number with 16 divisors.