The number 19722
19722 is a composite number with 16 divisors. Its prime factorisation is 2 × 3 × 19 × 173. Divisors (16): 1, 2, 3, 6, 19, 38, 57, 114, 173, 346, 519, 1038, 3287, 6574, 9861, 19722.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 19722: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
19722 is composite. Its prime factorisation is
- 3
The divisors add up to 41760; without 19722 itself that is 22038, so 19722 is abundant (22038 is more than 19722). Euler's totient φ(19722) = 6192 numbers up to 19722 share no factor with it.
- 4
The digits of 19722 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 74 steps to reach 1.
LaTeX source of the formulas on this page
\[ 19722 = 2 \times 3 \times 19 \times 173 \]
19722 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 41760 |
| Euler totient φ(n) | 6192 |
| Square | 388957284 |
| Cube | 7671015555048 |
| Square root | 140.435038 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 74 |
| Scientific notation | 1.9722 × |
19722 in other forms
| Form | Value |
|---|---|
| In words | nineteen thousand seven hundred and twenty-two |
| Binary (base 2) | 100110100001010 |
| Octal (base 8) | 46412 |
| Hexadecimal (base 16) | 4D0A |
| Base 3 | 1000001110 |
| As time | 19722 seconds = 5 h 28 min 42 s |
Is 19722 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (19722 ÷ 2 = 9861) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (19722 ÷ 3 = 6574) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | 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 | Yes (19722 ÷ 6 = 3287) | 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 | No (remainder 2) | 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 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 19722 a prime number?
No. 19722 = 2 × 3 × 19 × 173, so it is divisible by 2.
What are the factors of 19722?
1, 2, 3, 6, 19, 38, 57, 114, 173, 346, 519, 1038, 3287, 6574, 9861, 19722.
What is 19722 in binary?
100110100001010 (hexadecimal 4D0A, octal 46412).
What is the square root of 19722?
About 140.4350.
Is 19722 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 19722?
19722 is a happy number: repeatedly adding the squares of its digits reaches 1.