The number 42875

Q: Is 42875 a prime number?

No. 42875 = 5^3 × 7^3, so it is divisible by 5.

Q: What is special about the number 42875?

42875 is a perfect cube (35^3).

42875 is a perfect cube ( $35^{3}$ ). Its prime factorisation is $5^{3}$ × $7^{3}$ . Divisors (16): 1, 5, 7, 25, 35, 49, 125, 175, 245, 343, 875, 1225, 1715, 6125, 8575, 42875.

Number

Pick any whole number from 1 to 100,000.

42875 = 5^{3} \times 7^{3}

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How to work it out

1
What is special about 42875: a perfect cube ( $35^{3}$ ).
2
42875 is composite. Its prime factorisation is
$42875 = 5^{3} \times 7^{3}$
3
The divisors add up to 62400; without 42875 itself that is 19525, so 42875 is deficient (19525 is less than 42875). Euler's totient φ(42875) = 29400 numbers up to 42875 share no factor with it.
4
The digits of 42875 add up to 26, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 137 steps to reach 1.

LaTeX source of the formulas on this page

\[ 42875 = 5^{3} \times 7^{3} \]

42875 at a glance

Property	Value
Type	composite
Number of divisors	16
Sum of divisors	62400
Euler totient φ(n)	29400
Square	1838265625
Cube	78815638671875
Square root	207.062792 (= 35√35)
Digit sum / digital root	26 / 8
Collatz steps to 1	137
Scientific notation	4.2875 × $10^{4}$
Perfect power	$35^{3}$

42875 in other forms

Form	Value
In words	forty-two thousand eight hundred and seventy-five
Binary (base 2)	1010011101111011
Octal (base 8)	123573
Hexadecimal (base 16)	A77B
Base 3	2011210222
As time	42875 seconds = 11 h 54 min 35 s

Is 42875 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 2)	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	Yes (42875 ÷ 5 = 8575)	A number is divisible by 5 if the last digit is 0 or 5.
6	No (remainder 5)	A number is divisible by 6 if it is divisible by both 2 and 3.
7	Yes (42875 ÷ 7 = 6125)	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 8)	A number is divisible by 9 if the digits add up to a multiple of 9.
10	No (remainder 5)	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 11)	A number is divisible by 12 if it is divisible by both 3 and 4.

Questions

Is 42875 a prime number?

No. 42875 = $5^{3}$ × $7^{3}$ , so it is divisible by 5.

What are the factors of 42875?

1, 5, 7, 25, 35, 49, 125, 175, 245, 343, 875, 1225, 1715, 6125, 8575, 42875.

What is 42875 in binary?

1010011101111011 (hexadecimal A77B, octal 123573).

What is the square root of 42875?

About 207.0628, exactly 35√35.

Is 42875 divisible by 3?

No. Its digits add up to 26, which is not a multiple of 3.

What is special about the number 42875?

42875 is a perfect cube ( $35^{3}$ ).