The number 42521
42521 is a composite number with 4 divisors. Its prime factorisation is 101 × 421. Divisors (4): 1, 101, 421, 42521.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42521: a semiprime: 101 × 421, the product of two primes.
- 2
42521 is composite. Its prime factorisation is
- 3
The divisors add up to 43044; without 42521 itself that is 523, so 42521 is deficient (523 is less than 42521). Euler's totient φ(42521) = 42000 numbers up to 42521 share no factor with it.
- 4
The digits of 42521 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 62 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42521 = 101 \times 421 \]
42521 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 43044 |
| Euler totient φ(n) | 42000 |
| Square | 1808035441 |
| Cube | 76879474986761 |
| Square root | 206.206207 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 62 |
| Scientific notation | 4.2521 × |
42521 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand five hundred and twenty-one |
| Binary (base 2) | 1010011000011001 |
| Octal (base 8) | 123031 |
| Hexadecimal (base 16) | A619 |
| Base 3 | 2011022212 |
| As time | 42521 seconds = 11 h 48 min 41 s |
Is 42521 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 2) | 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 5) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | 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 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42521 a prime number?
No. 42521 = 101 × 421, so it is divisible by 101.
What are the factors of 42521?
1, 101, 421, 42521.
What is 42521 in binary?
1010011000011001 (hexadecimal A619, octal 123031).
What is the square root of 42521?
About 206.2062.
Is 42521 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 42521?
42521 is a semiprime: 101 × 421, the product of two primes.