The number 15001
15001 is a composite number with 4 divisors. Its prime factorisation is 7 × 2143. Divisors (4): 1, 7, 2143, 15001.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 15001: a Harshad number: divisible by its digit sum 7; a semiprime: 7 × 2143, the product of two primes.
- 2
15001 is composite. Its prime factorisation is
- 3
The divisors add up to 17152; without 15001 itself that is 2151, so 15001 is deficient (2151 is less than 15001). Euler's totient φ(15001) = 12852 numbers up to 15001 share no factor with it.
- 4
The digits of 15001 add up to 7, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 164 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15001 = 7 \times 2143 \]
15001 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 17152 |
| Euler totient φ(n) | 12852 |
| Square | 225030001 |
| Cube | 3375675045001 |
| Square root | 122.478570 |
| Digit sum / digital root | 7 / 7 |
| Collatz steps to 1 | 164 |
| Scientific notation | 1.5001 × |
15001 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand and one |
| Binary (base 2) | 11101010011001 |
| Octal (base 8) | 35231 |
| Hexadecimal (base 16) | 3A99 |
| Base 3 | 202120121 |
| As time | 15001 seconds = 4 h 10 min 1 s |
Is 15001 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 | Yes (15001 ÷ 7 = 2143) | 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 7) | 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 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 15001 a prime number?
No. 15001 = 7 × 2143, so it is divisible by 7.
What are the factors of 15001?
1, 7, 2143, 15001.
What is 15001 in binary?
11101010011001 (hexadecimal 3A99, octal 35231).
What is the square root of 15001?
About 122.4786.
Is 15001 divisible by 3?
No. Its digits add up to 7, which is not a multiple of 3.
What is special about the number 15001?
15001 is a Harshad number: divisible by its digit sum 7; a semiprime: 7 × 2143, the product of two primes.