The number 72091
72091 is a twin prime (72089 and 72091 are both prime) and the 7137th prime number. Its only divisors are 1 and 72091.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72091: a twin prime (72089 and 72091 are both prime); the 7137th prime number.
- 2
72091 is prime, so its only factors are 1 and 72091. It is the 7137th prime; the next prime is 72101 and the one before is 72089.
- 3
The divisors add up to 72092; without 72091 itself that is 1, so 72091 is deficient (1 is less than 72091). Euler's totient φ(72091) = 72090 numbers up to 72091 share no factor with it.
- 4
The digits of 72091 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 112 steps to reach 1.
72091 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 72092 |
| Euler totient φ(n) | 72090 |
| Square | 5197112281 |
| Cube | 374665021449571 |
| Square root | 268.497672 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 112 |
| Scientific notation | 7.2091 × |
72091 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand and ninety-one |
| Binary (base 2) | 10001100110011011 |
| Octal (base 8) | 214633 |
| Hexadecimal (base 16) | 1199B |
| Base 3 | 10122220001 |
| As time | 72091 seconds = 20 h 1 min 31 s |
Is 72091 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 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 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 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72091 a prime number?
Yes. 72091 is divisible only by 1 and itself.
What are the factors of 72091?
1, 72091.
What is 72091 in binary?
10001100110011011 (hexadecimal 1199B, octal 214633).
What is the square root of 72091?
About 268.4977.
Is 72091 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 72091?
72091 is a twin prime (72089 and 72091 are both prime); the 7137th prime number.