The number 21472
21472 is a composite number with 24 divisors. Its prime factorisation is × 11 × 61. Divisors (24): 1, 2, 4, 8, 11, 16, 22, 32, 44, 61, 88, 122, 176, 244, 352, 488 … 21472.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21472: a Harshad number: divisible by its digit sum 16.
- 2
21472 is composite. Its prime factorisation is
- 3
The divisors add up to 46872; without 21472 itself that is 25400, so 21472 is abundant (25400 is more than 21472). Euler's totient φ(21472) = 9600 numbers up to 21472 share no factor with it.
- 4
The digits of 21472 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 100 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21472 = 2^{5} \times 11 \times 61 \]21472 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 46872 |
| Euler totient φ(n) | 9600 |
| Square | 461046784 |
| Cube | 9899596546048 |
| Square root | 146.533273 (= 4√1342) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 100 |
| Scientific notation | 2.1472 × |
21472 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand four hundred and seventy-two |
| Binary (base 2) | 101001111100000 |
| Octal (base 8) | 51740 |
| Hexadecimal (base 16) | 53E0 |
| Base 3 | 1002110021 |
| As time | 21472 seconds = 5 h 57 min 52 s |
Is 21472 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21472 ÷ 2 = 10736) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (21472 ÷ 4 = 5368) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 | Yes (21472 ÷ 8 = 2684) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (21472 ÷ 11 = 1952) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21472 a prime number?
No. 21472 = × 11 × 61, so it is divisible by 2.
What are the factors of 21472?
1, 2, 4, 8, 11, 16, 22, 32, 44, 61, 88, 122, 176, 244, 352, 488, 671, 976, 1342, 1952, 2684, 5368, 10736, 21472.
What is 21472 in binary?
101001111100000 (hexadecimal 53E0, octal 51740).
What is the square root of 21472?
About 146.5333, exactly 4√1342.
Is 21472 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 21472?
21472 is a Harshad number: divisible by its digit sum 16.