The number 72187
72187 is a composite number with 4 divisors. Its prime factorisation is 37 × 1951. Divisors (4): 1, 37, 1951, 72187.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72187: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 37 × 1951, the product of two primes.
- 2
72187 is composite. Its prime factorisation is
- 3
The divisors add up to 74176; without 72187 itself that is 1989, so 72187 is deficient (1989 is less than 72187). Euler's totient φ(72187) = 70200 numbers up to 72187 share no factor with it.
- 4
The digits of 72187 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 42 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72187 = 37 \times 1951 \]
72187 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 74176 |
| Euler totient φ(n) | 70200 |
| Square | 5210962969 |
| Cube | 376163783843203 |
| Square root | 268.676385 |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 42 |
| Scientific notation | 7.2187 × |
72187 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand one hundred and eighty-seven |
| Binary (base 2) | 10001100111111011 |
| Octal (base 8) | 214773 |
| Hexadecimal (base 16) | 119FB |
| Base 3 | 10200000121 |
| As time | 72187 seconds = 20 h 3 min 7 s |
Is 72187 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 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | 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 5) | 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 72187 a prime number?
No. 72187 = 37 × 1951, so it is divisible by 37.
What are the factors of 72187?
1, 37, 1951, 72187.
What is 72187 in binary?
10001100111111011 (hexadecimal 119FB, octal 214773).
What is the square root of 72187?
About 268.6764.
Is 72187 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 72187?
72187 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 37 × 1951, the product of two primes.