The number 19988
19988 is a composite number with 12 divisors. Its prime factorisation is × 19 × 263. Divisors (12): 1, 2, 4, 19, 38, 76, 263, 526, 1052, 4997, 9994, 19988.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 19988: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
19988 is composite. Its prime factorisation is
- 3
The divisors add up to 36960; without 19988 itself that is 16972, so 19988 is deficient (16972 is less than 19988). Euler's totient φ(19988) = 9432 numbers up to 19988 share no factor with it.
- 4
The digits of 19988 add up to 35, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 180 steps to reach 1.
LaTeX source of the formulas on this page
\[ 19988 = 2^{2} \times 19 \times 263 \]19988 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 36960 |
| Euler totient φ(n) | 9432 |
| Square | 399520144 |
| Cube | 7985608638272 |
| Square root | 141.378923 (= 2√4997) |
| Digit sum / digital root | 35 / 8 |
| Collatz steps to 1 | 180 |
| Scientific notation | 1.9988 × |
19988 in other forms
| Form | Value |
|---|---|
| In words | nineteen thousand nine hundred and eighty-eight |
| Binary (base 2) | 100111000010100 |
| Octal (base 8) | 47024 |
| Hexadecimal (base 16) | 4E14 |
| Base 3 | 1000102022 |
| As time | 19988 seconds = 5 h 33 min 8 s |
Is 19988 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (19988 ÷ 2 = 9994) | 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 | Yes (19988 ÷ 4 = 4997) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 19988 a prime number?
No. 19988 = × 19 × 263, so it is divisible by 2.
What are the factors of 19988?
1, 2, 4, 19, 38, 76, 263, 526, 1052, 4997, 9994, 19988.
What is 19988 in binary?
100111000010100 (hexadecimal 4E14, octal 47024).
What is the square root of 19988?
About 141.3789, exactly 2√4997.
Is 19988 divisible by 3?
No. Its digits add up to 35, which is not a multiple of 3.
What is special about the number 19988?
19988 is a happy number: repeatedly adding the squares of its digits reaches 1.