The number 72215
72215 is a composite number with 16 divisors. Its prime factorisation is 5 × 11 × 13 × 101. Divisors (16): 1, 5, 11, 13, 55, 65, 101, 143, 505, 715, 1111, 1313, 5555, 6565, 14443, 72215.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
72215 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
72215 is composite. Its prime factorisation is
- 3
The divisors add up to 102816; without 72215 itself that is 30601, so 72215 is deficient (30601 is less than 72215). Euler's totient φ(72215) = 48000 numbers up to 72215 share no factor with it.
- 4
The digits of 72215 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 94 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72215 = 5 \times 11 \times 13 \times 101 \]
72215 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 102816 |
| Euler totient φ(n) | 48000 |
| Square | 5215006225 |
| Cube | 376601674538375 |
| Square root | 268.728488 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 94 |
| Scientific notation | 7.2215 × |
72215 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand two hundred and fifteen |
| Binary (base 2) | 10001101000010111 |
| Octal (base 8) | 215027 |
| Hexadecimal (base 16) | 11A17 |
| Base 3 | 10200001122 |
| As time | 72215 seconds = 20 h 3 min 35 s |
Is 72215 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 | Yes (72215 ÷ 5 = 14443) | 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 7) | 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 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (72215 ÷ 11 = 6565) | 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 72215 a prime number?
No. 72215 = 5 × 11 × 13 × 101, so it is divisible by 5.
What are the factors of 72215?
1, 5, 11, 13, 55, 65, 101, 143, 505, 715, 1111, 1313, 5555, 6565, 14443, 72215.
What is 72215 in binary?
10001101000010111 (hexadecimal 11A17, octal 215027).
What is the square root of 72215?
About 268.7285.
Is 72215 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 72215?
It is a composite number with 16 divisors.