The number 15942
15942 is a composite number with 8 divisors. Its prime factorisation is 2 × 3 × 2657. Divisors (8): 1, 2, 3, 6, 2657, 5314, 7971, 15942.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
15942 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
15942 is composite. Its prime factorisation is
- 3
The divisors add up to 31896; without 15942 itself that is 15954, so 15942 is abundant (15954 is more than 15942). Euler's totient φ(15942) = 5312 numbers up to 15942 share no factor with it.
- 4
The digits of 15942 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 53 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15942 = 2 \times 3 \times 2657 \]
15942 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 31896 |
| Euler totient φ(n) | 5312 |
| Square | 254147364 |
| Cube | 4051617276888 |
| Square root | 126.261633 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 53 |
| Scientific notation | 1.5942 × |
15942 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand nine hundred and forty-two |
| Binary (base 2) | 11111001000110 |
| Octal (base 8) | 37106 |
| Hexadecimal (base 16) | 3E46 |
| Base 3 | 210212110 |
| As time | 15942 seconds = 4 h 25 min 42 s |
Is 15942 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (15942 ÷ 2 = 7971) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (15942 ÷ 3 = 5314) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | 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 | Yes (15942 ÷ 6 = 2657) | 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 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 15942 a prime number?
No. 15942 = 2 × 3 × 2657, so it is divisible by 2.
What are the factors of 15942?
1, 2, 3, 6, 2657, 5314, 7971, 15942.
What is 15942 in binary?
11111001000110 (hexadecimal 3E46, octal 37106).
What is the square root of 15942?
About 126.2616.
Is 15942 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 15942?
It is a composite number with 8 divisors.