The number 15801
15801 is a composite number with 8 divisors. Its prime factorisation is 3 × 23 × 229. Divisors (8): 1, 3, 23, 69, 229, 687, 5267, 15801.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 15801: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
15801 is composite. Its prime factorisation is
- 3
The divisors add up to 22080; without 15801 itself that is 6279, so 15801 is deficient (6279 is less than 15801). Euler's totient φ(15801) = 10032 numbers up to 15801 share no factor with it.
- 4
The digits of 15801 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 40 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15801 = 3 \times 23 \times 229 \]
15801 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 22080 |
| Euler totient φ(n) | 10032 |
| Square | 249671601 |
| Cube | 3945060967401 |
| Square root | 125.702029 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 40 |
| Scientific notation | 1.5801 × |
15801 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand eight hundred and one |
| Binary (base 2) | 11110110111001 |
| Octal (base 8) | 36671 |
| Hexadecimal (base 16) | 3DB9 |
| Base 3 | 210200020 |
| As time | 15801 seconds = 4 h 23 min 21 s |
Is 15801 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 | Yes (15801 ÷ 3 = 5267) | 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 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 6) | 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 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 15801 a prime number?
No. 15801 = 3 × 23 × 229, so it is divisible by 3.
What are the factors of 15801?
1, 3, 23, 69, 229, 687, 5267, 15801.
What is 15801 in binary?
11110110111001 (hexadecimal 3DB9, octal 36671).
What is the square root of 15801?
About 125.7020.
Is 15801 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 15801?
15801 is a happy number: repeatedly adding the squares of its digits reaches 1.