The number 80521
80521 is a composite number with 4 divisors. Its prime factorisation is 7 × 11503. Divisors (4): 1, 7, 11503, 80521.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 80521: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 7 × 11503, the product of two primes.
- 2
80521 is composite. Its prime factorisation is
- 3
The divisors add up to 92032; without 80521 itself that is 11511, so 80521 is deficient (11511 is less than 80521). Euler's totient φ(80521) = 69012 numbers up to 80521 share no factor with it.
- 4
The digits of 80521 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 213 steps to reach 1.
LaTeX source of the formulas on this page
\[ 80521 = 7 \times 11503 \]
80521 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 92032 |
| Euler totient φ(n) | 69012 |
| Square | 6483631441 |
| Cube | 522068487260761 |
| Square root | 283.762224 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 213 |
| Scientific notation | 8.0521 × |
80521 in other forms
| Form | Value |
|---|---|
| In words | eighty thousand five hundred and twenty-one |
| Binary (base 2) | 10011101010001001 |
| Octal (base 8) | 235211 |
| Hexadecimal (base 16) | 13A89 |
| Base 3 | 11002110021 |
| As time | 80521 seconds = 22 h 22 min 1 s |
Is 80521 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 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | 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 | Yes (80521 ÷ 7 = 11503) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | 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 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 80521 a prime number?
No. 80521 = 7 × 11503, so it is divisible by 7.
What are the factors of 80521?
1, 7, 11503, 80521.
What is 80521 in binary?
10011101010001001 (hexadecimal 13A89, octal 235211).
What is the square root of 80521?
About 283.7622.
Is 80521 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 80521?
80521 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 7 × 11503, the product of two primes.