The number 16445
16445 is a composite number with 16 divisors. Its prime factorisation is 5 × 11 × 13 × 23. Divisors (16): 1, 5, 11, 13, 23, 55, 65, 115, 143, 253, 299, 715, 1265, 1495, 3289, 16445.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 16445: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
16445 is composite. Its prime factorisation is
- 3
The divisors add up to 24192; without 16445 itself that is 7747, so 16445 is deficient (7747 is less than 16445). Euler's totient φ(16445) = 10560 numbers up to 16445 share no factor with it.
- 4
The digits of 16445 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 40 steps to reach 1.
LaTeX source of the formulas on this page
\[ 16445 = 5 \times 11 \times 13 \times 23 \]
16445 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 24192 |
| Euler totient φ(n) | 10560 |
| Square | 270438025 |
| Cube | 4447353321125 |
| Square root | 128.238060 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 40 |
| Scientific notation | 1.6445 × |
16445 in other forms
| Form | Value |
|---|---|
| In words | sixteen thousand four hundred and forty-five |
| Binary (base 2) | 100000000111101 |
| Octal (base 8) | 40075 |
| Hexadecimal (base 16) | 403D |
| Base 3 | 211120002 |
| As time | 16445 seconds = 4 h 34 min 5 s |
Is 16445 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 | Yes (16445 ÷ 5 = 3289) | 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 2) | 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 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (16445 ÷ 11 = 1495) | 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 16445 a prime number?
No. 16445 = 5 × 11 × 13 × 23, so it is divisible by 5.
What are the factors of 16445?
1, 5, 11, 13, 23, 55, 65, 115, 143, 253, 299, 715, 1265, 1495, 3289, 16445.
What is 16445 in binary?
100000000111101 (hexadecimal 403D, octal 40075).
What is the square root of 16445?
About 128.2381.
Is 16445 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 16445?
16445 is a happy number: repeatedly adding the squares of its digits reaches 1.