The number 72397
72397 is a composite number with 4 divisors. Its prime factorisation is 13 × 5569. Divisors (4): 1, 13, 5569, 72397.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72397: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 13 × 5569, the product of two primes.
- 2
72397 is composite. Its prime factorisation is
- 3
The divisors add up to 77980; without 72397 itself that is 5583, so 72397 is deficient (5583 is less than 72397). Euler's totient φ(72397) = 66816 numbers up to 72397 share no factor with it.
- 4
The digits of 72397 add up to 28, 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
\[ 72397 = 13 \times 5569 \]
72397 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 77980 |
| Euler totient φ(n) | 66816 |
| Square | 5241325609 |
| Cube | 379456250114773 |
| Square root | 269.066906 |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 50 |
| Scientific notation | 7.2397 × |
72397 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand three hundred and ninety-seven |
| Binary (base 2) | 10001101011001101 |
| Octal (base 8) | 215315 |
| Hexadecimal (base 16) | 11ACD |
| Base 3 | 10200022101 |
| As time | 72397 seconds = 20 h 6 min 37 s |
Is 72397 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 2) | 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 5) | 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 7) | 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 72397 a prime number?
No. 72397 = 13 × 5569, so it is divisible by 13.
What are the factors of 72397?
1, 13, 5569, 72397.
What is 72397 in binary?
10001101011001101 (hexadecimal 11ACD, octal 215315).
What is the square root of 72397?
About 269.0669.
Is 72397 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 72397?
72397 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 13 × 5569, the product of two primes.