The number 2019
2019 is a composite number with 4 divisors. Its prime factorisation is 3 × 673. Divisors (4): 1, 3, 673, 2019.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 2019: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 3 × 673, the product of two primes.
- 2
2019 is composite. Its prime factorisation is
- 3
The divisors add up to 2696; without 2019 itself that is 677, so 2019 is deficient (677 is less than 2019). Euler's totient φ(2019) = 1344 numbers up to 2019 share no factor with it.
- 4
The digits of 2019 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 112 steps to reach 1.
LaTeX source of the formulas on this page
\[ 2019 = 3 \times 673 \]
2019 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 2696 |
| Euler totient φ(n) | 1344 |
| Square | 4076361 |
| Cube | 8230172859 |
| Square root | 44.933284 |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 112 |
| Scientific notation | 2.019 × |
2019 in other forms
| Form | Value |
|---|---|
| In words | two thousand and nineteen |
| Roman numerals | MMXIX |
| Binary (base 2) | 11111100011 |
| Octal (base 8) | 3743 |
| Hexadecimal (base 16) | 7E3 |
| Base 3 | 2202210 |
| As time | 2019 seconds = 33 min 39 s |
Is 2019 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 (2019 ÷ 3 = 673) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | 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 | 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 3) | 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 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 2019 a prime number?
No. 2019 = 3 × 673, so it is divisible by 3.
What are the factors of 2019?
1, 3, 673, 2019.
What is 2019 in binary?
11111100011 (hexadecimal 7E3, octal 3743).
What is the square root of 2019?
About 44.9333.
What is 2019 in Roman numerals?
MMXIX.
Is 2019 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 2019?
2019 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 3 × 673, the product of two primes.