The number 1639
1639 is a composite number with 4 divisors. Its prime factorisation is 11 × 149. Divisors (4): 1, 11, 149, 1639.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1639: a semiprime: 11 × 149, the product of two primes.
- 2
1639 is composite. Its prime factorisation is
- 3
The divisors add up to 1800; without 1639 itself that is 161, so 1639 is deficient (161 is less than 1639). Euler's totient φ(1639) = 1480 numbers up to 1639 share no factor with it.
- 4
The digits of 1639 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 104 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1639 = 11 \times 149 \]
1639 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 1800 |
| Euler totient φ(n) | 1480 |
| Square | 2686321 |
| Cube | 4402880119 |
| Square root | 40.484565 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 104 |
| Scientific notation | 1.639 × |
1639 in other forms
| Form | Value |
|---|---|
| In words | one thousand six hundred and thirty-nine |
| Roman numerals | MDCXXXIX |
| Binary (base 2) | 11001100111 |
| Octal (base 8) | 3147 |
| Hexadecimal (base 16) | 667 |
| Base 3 | 2020201 |
| As time | 1639 seconds = 27 min 19 s |
Is 1639 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 1) | 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | 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 | Yes (1639 ÷ 11 = 149) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1639 a prime number?
No. 1639 = 11 × 149, so it is divisible by 11.
What are the factors of 1639?
1, 11, 149, 1639.
What is 1639 in binary?
11001100111 (hexadecimal 667, octal 3147).
What is the square root of 1639?
About 40.4846.
What is 1639 in Roman numerals?
MDCXXXIX.
Is 1639 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 1639?
1639 is a semiprime: 11 × 149, the product of two primes.