The number 72971
72971 is a composite number with 4 divisors. Its prime factorisation is 43 × 1697. Divisors (4): 1, 43, 1697, 72971.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72971: a semiprime: 43 × 1697, the product of two primes.
- 2
72971 is composite. Its prime factorisation is
- 3
The divisors add up to 74712; without 72971 itself that is 1741, so 72971 is deficient (1741 is less than 72971). Euler's totient φ(72971) = 71232 numbers up to 72971 share no factor with it.
- 4
The digits of 72971 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 68 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72971 = 43 \times 1697 \]
72971 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 74712 |
| Euler totient φ(n) | 71232 |
| Square | 5324766841 |
| Cube | 388553561154611 |
| Square root | 270.131449 |
| Digit sum / digital root | 26 / 8 |
| Collatz steps to 1 | 68 |
| Scientific notation | 7.2971 × |
72971 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand nine hundred and seventy-one |
| Binary (base 2) | 10001110100001011 |
| Octal (base 8) | 216413 |
| Hexadecimal (base 16) | 11D0B |
| Base 3 | 10201002122 |
| As time | 72971 seconds = 20 h 16 min 11 s |
Is 72971 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 3) | 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 3) | 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 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72971 a prime number?
No. 72971 = 43 × 1697, so it is divisible by 43.
What are the factors of 72971?
1, 43, 1697, 72971.
What is 72971 in binary?
10001110100001011 (hexadecimal 11D0B, octal 216413).
What is the square root of 72971?
About 270.1314.
Is 72971 divisible by 3?
No. Its digits add up to 26, which is not a multiple of 3.
What is special about the number 72971?
72971 is a semiprime: 43 × 1697, the product of two primes.