The number 80990
80990 is a composite number with 32 divisors. Its prime factorisation is 2 × 5 × 7 × 13 × 89. Divisors (32): 1, 2, 5, 7, 10, 13, 14, 26, 35, 65, 70, 89, 91, 130, 178, 182 … 80990.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 80990: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 26.
- 2
80990 is composite. Its prime factorisation is
- 3
The divisors add up to 181440; without 80990 itself that is 100450, so 80990 is abundant (100450 is more than 80990). Euler's totient φ(80990) = 25344 numbers up to 80990 share no factor with it.
- 4
The digits of 80990 add up to 26, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 89 steps to reach 1.
LaTeX source of the formulas on this page
\[ 80990 = 2 \times 5 \times 7 \times 13 \times 89 \]
80990 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 181440 |
| Euler totient φ(n) | 25344 |
| Square | 6559380100 |
| Cube | 531244194299000 |
| Square root | 284.587421 |
| Digit sum / digital root | 26 / 8 |
| Collatz steps to 1 | 89 |
| Scientific notation | 8.099 × |
80990 in other forms
| Form | Value |
|---|---|
| In words | eighty thousand nine hundred and ninety |
| Binary (base 2) | 10011110001011110 |
| Octal (base 8) | 236136 |
| Hexadecimal (base 16) | 13C5E |
| Base 3 | 11010002122 |
| As time | 80990 seconds = 22 h 29 min 50 s |
Is 80990 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (80990 ÷ 2 = 40495) | 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 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (80990 ÷ 5 = 16198) | 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 | Yes (80990 ÷ 7 = 11570) | 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 6) | 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 | Yes (80990 ÷ 10 = 8099) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 80990 a prime number?
No. 80990 = 2 × 5 × 7 × 13 × 89, so it is divisible by 2.
What are the factors of 80990?
1, 2, 5, 7, 10, 13, 14, 26, 35, 65, 70, 89, 91, 130, 178, 182, 445, 455, 623, 890, 910, 1157, 1246, 2314, 3115, 5785, 6230, 8099, 11570, 16198, 40495, 80990.
What is 80990 in binary?
10011110001011110 (hexadecimal 13C5E, octal 236136).
What is the square root of 80990?
About 284.5874.
Is 80990 divisible by 3?
No. Its digits add up to 26, which is not a multiple of 3.
What is special about the number 80990?
80990 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 26.