The number 71801
71801 is a composite number with 4 divisors. Its prime factorisation is 19 × 3779. Divisors (4): 1, 19, 3779, 71801.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 71801: a semiprime: 19 × 3779, the product of two primes.
- 2
71801 is composite. Its prime factorisation is
- 3
The divisors add up to 75600; without 71801 itself that is 3799, so 71801 is deficient (3799 is less than 71801). Euler's totient φ(71801) = 68004 numbers up to 71801 share no factor with it.
- 4
The digits of 71801 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 156 steps to reach 1.
LaTeX source of the formulas on this page
\[ 71801 = 19 \times 3779 \]
71801 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 75600 |
| Euler totient φ(n) | 68004 |
| Square | 5155383601 |
| Cube | 370161697935401 |
| Square root | 267.957086 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 156 |
| Scientific notation | 7.1801 × |
71801 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand eight hundred and one |
| Binary (base 2) | 10001100001111001 |
| Octal (base 8) | 214171 |
| Hexadecimal (base 16) | 11879 |
| Base 3 | 10122111022 |
| As time | 71801 seconds = 19 h 56 min 41 s |
Is 71801 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 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 1) | 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 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | 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 71801 a prime number?
No. 71801 = 19 × 3779, so it is divisible by 19.
What are the factors of 71801?
1, 19, 3779, 71801.
What is 71801 in binary?
10001100001111001 (hexadecimal 11879, octal 214171).
What is the square root of 71801?
About 267.9571.
Is 71801 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 71801?
71801 is a semiprime: 19 × 3779, the product of two primes.