The number 42156
42156 is a composite number with 18 divisors. Its prime factorisation is × × 1171. Divisors (18): 1, 2, 3, 4, 6, 9, 12, 18, 36, 1171, 2342, 3513, 4684, 7026, 10539, 14052 … 42156.
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How to work it out
- 1
What is special about 42156: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.
- 2
42156 is composite. Its prime factorisation is
- 3
The divisors add up to 106652; without 42156 itself that is 64496, so 42156 is abundant (64496 is more than 42156). Euler's totient φ(42156) = 14040 numbers up to 42156 share no factor with it.
- 4
The digits of 42156 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 194 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42156 = 2^{2} \times 3^{2} \times 1171 \]42156 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 18 |
| Sum of divisors | 106652 |
| Euler totient φ(n) | 14040 |
| Square | 1777128336 |
| Cube | 74916622132416 |
| Square root | 205.319264 (= 6√1171) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 194 |
| Scientific notation | 4.2156 × |
42156 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand one hundred and fifty-six |
| Binary (base 2) | 1010010010101100 |
| Octal (base 8) | 122254 |
| Hexadecimal (base 16) | A4AC |
| Base 3 | 2010211100 |
| As time | 42156 seconds = 11 h 42 min 36 s |
Is 42156 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42156 ÷ 2 = 21078) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (42156 ÷ 3 = 14052) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (42156 ÷ 4 = 10539) | 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 | Yes (42156 ÷ 6 = 7026) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (42156 ÷ 9 = 4684) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 6) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (42156 ÷ 12 = 3513) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42156 a prime number?
No. 42156 = × × 1171, so it is divisible by 2.
What are the factors of 42156?
1, 2, 3, 4, 6, 9, 12, 18, 36, 1171, 2342, 3513, 4684, 7026, 10539, 14052, 21078, 42156.
What is 42156 in binary?
1010010010101100 (hexadecimal A4AC, octal 122254).
What is the square root of 42156?
About 205.3193, exactly 6√1171.
Is 42156 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 42156?
42156 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.