The number 72001
72001 is a composite number with 4 divisors. Its prime factorisation is 89 × 809. Divisors (4): 1, 89, 809, 72001.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72001: a semiprime: 89 × 809, the product of two primes.
- 2
72001 is composite. Its prime factorisation is
- 3
The divisors add up to 72900; without 72001 itself that is 899, so 72001 is deficient (899 is less than 72001). Euler's totient φ(72001) = 71104 numbers up to 72001 share no factor with it.
- 4
The digits of 72001 add up to 10, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 50 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72001 = 89 \times 809 \]
72001 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 72900 |
| Euler totient φ(n) | 71104 |
| Square | 5184144001 |
| Cube | 373263552216001 |
| Square root | 268.330021 |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 50 |
| Scientific notation | 7.2001 × |
72001 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand and one |
| Binary (base 2) | 10001100101000001 |
| Octal (base 8) | 214501 |
| Hexadecimal (base 16) | 11941 |
| Base 3 | 10122202201 |
| As time | 72001 seconds = 20 h 0 min 1 s |
Is 72001 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 6) | 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 6) | 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 72001 a prime number?
No. 72001 = 89 × 809, so it is divisible by 89.
What are the factors of 72001?
1, 89, 809, 72001.
What is 72001 in binary?
10001100101000001 (hexadecimal 11941, octal 214501).
What is the square root of 72001?
About 268.3300.
Is 72001 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 72001?
72001 is a semiprime: 89 × 809, the product of two primes.