The number 71641
71641 is a composite number with 4 divisors. Its prime factorisation is 31 × 2311. Divisors (4): 1, 31, 2311, 71641.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 71641: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 31 × 2311, the product of two primes.
- 2
71641 is composite. Its prime factorisation is
- 3
The divisors add up to 73984; without 71641 itself that is 2343, so 71641 is deficient (2343 is less than 71641). Euler's totient φ(71641) = 69300 numbers up to 71641 share no factor with it.
- 4
The digits of 71641 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 94 steps to reach 1.
LaTeX source of the formulas on this page
\[ 71641 = 31 \times 2311 \]
71641 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 73984 |
| Euler totient φ(n) | 69300 |
| Square | 5132432881 |
| Cube | 367692624027721 |
| Square root | 267.658364 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 94 |
| Scientific notation | 7.1641 × |
71641 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand six hundred and forty-one |
| Binary (base 2) | 10001011111011001 |
| Octal (base 8) | 213731 |
| Hexadecimal (base 16) | 117D9 |
| Base 3 | 10122021101 |
| As time | 71641 seconds = 19 h 54 min 1 s |
Is 71641 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 | 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 1) | 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 9) | 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 71641 a prime number?
No. 71641 = 31 × 2311, so it is divisible by 31.
What are the factors of 71641?
1, 31, 2311, 71641.
What is 71641 in binary?
10001011111011001 (hexadecimal 117D9, octal 213731).
What is the square root of 71641?
About 267.6584.
Is 71641 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 71641?
71641 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 31 × 2311, the product of two primes.