The number 4090
4090 is a composite number with 8 divisors. Its prime factorisation is 2 × 5 × 409. Divisors (8): 1, 2, 5, 10, 409, 818, 2045, 4090.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 4090: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
4090 is composite. Its prime factorisation is
- 3
The divisors add up to 7380; without 4090 itself that is 3290, so 4090 is deficient (3290 is less than 4090). Euler's totient φ(4090) = 1632 numbers up to 4090 share no factor with it.
- 4
The digits of 4090 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 64 steps to reach 1.
LaTeX source of the formulas on this page
\[ 4090 = 2 \times 5 \times 409 \]
4090 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 7380 |
| Euler totient φ(n) | 1632 |
| Square | 16728100 |
| Cube | 68417929000 |
| Square root | 63.953108 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 64 |
| Scientific notation | 4.09 × |
4090 in other forms
| Form | Value |
|---|---|
| In words | four thousand and ninety |
| Binary (base 2) | 111111111010 |
| Octal (base 8) | 7772 |
| Hexadecimal (base 16) | FFA |
| Base 3 | 12121111 |
| As time | 4090 seconds = 1 h 8 min 10 s |
Is 4090 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (4090 ÷ 2 = 2045) | 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 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (4090 ÷ 5 = 818) | 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 2) | 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 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (4090 ÷ 10 = 409) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 4090 a prime number?
No. 4090 = 2 × 5 × 409, so it is divisible by 2.
What are the factors of 4090?
1, 2, 5, 10, 409, 818, 2045, 4090.
What is 4090 in binary?
111111111010 (hexadecimal FFA, octal 7772).
What is the square root of 4090?
About 63.9531.
Is 4090 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 4090?
4090 is a happy number: repeatedly adding the squares of its digits reaches 1.