The number 84840

Q: Is 84840 a prime number?

No. 84840 = 2^3 × 3 × 5 × 7 × 101, so it is divisible by 2.

84840 is a composite number with 64 divisors. Its prime factorisation is $2^{3}$ × 3 × 5 × 7 × 101. Divisors (64): 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 20, 21, 24, 28 … 84840.

Number

Pick any whole number from 1 to 100,000.

84840 = 2^{3} \times 3 \times 5 \times 7 \times 101

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How to work it out

1
What is special about 84840: a Harshad number: divisible by its digit sum 24.
2
84840 is composite. Its prime factorisation is
$84840 = 2^{3} \times 3 \times 5 \times 7 \times 101$
3
The divisors add up to 293760; without 84840 itself that is 208920, so 84840 is abundant (208920 is more than 84840). Euler's totient φ(84840) = 19200 numbers up to 84840 share no factor with it.
4
The digits of 84840 add up to 24, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 151 steps to reach 1.

LaTeX source of the formulas on this page

\[ 84840 = 2^{3} \times 3 \times 5 \times 7 \times 101 \]

84840 at a glance

Property	Value
Type	composite
Number of divisors	64
Sum of divisors	293760
Euler totient φ(n)	19200
Square	7197825600
Cube	610663523904000
Square root	291.273068 (= 2√21210)
Digit sum / digital root	24 / 6
Collatz steps to 1	151
Scientific notation	8.484 × $10^{4}$

84840 in other forms

Form	Value
In words	eighty-four thousand eight hundred and forty
Binary (base 2)	10100101101101000
Octal (base 8)	245550
Hexadecimal (base 16)	14B68
Base 3	11022101020
As time	84840 seconds = 23 h 34 min 0 s

Is 84840 divisible by 2 to 12?

Divisor	Answer	Rule
2	Yes (84840 ÷ 2 = 42420)	A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8).
3	Yes (84840 ÷ 3 = 28280)	A number is divisible by 3 if the digits add up to a multiple of 3.
4	Yes (84840 ÷ 4 = 21210)	A number is divisible by 4 if the last two digits make a multiple of 4.
5	Yes (84840 ÷ 5 = 16968)	A number is divisible by 5 if the last digit is 0 or 5.
6	Yes (84840 ÷ 6 = 14140)	A number is divisible by 6 if it is divisible by both 2 and 3.
7	Yes (84840 ÷ 7 = 12120)	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	Yes (84840 ÷ 8 = 10605)	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	Yes (84840 ÷ 10 = 8484)	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	Yes (84840 ÷ 12 = 7070)	A number is divisible by 12 if it is divisible by both 3 and 4.

Questions

Is 84840 a prime number?

No. 84840 = $2^{3}$ × 3 × 5 × 7 × 101, so it is divisible by 2.

What are the factors of 84840?

1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 20, 21, 24, 28, 30, 35, 40, 42, 56, 60, 70, 84, 101, 105, 120, 140, 168, 202, 210, 280, 303, 404, 420, 505, 606, 707, 808, 840, 1010, 1212, 1414, 1515, 2020, 2121, 2424, 2828, 3030, 3535, 4040, 4242, 5656, 6060, 7070, 8484, 10605, 12120, 14140, 16968, 21210, 28280, 42420, 84840.

What is 84840 in binary?

10100101101101000 (hexadecimal 14B68, octal 245550).

What is the square root of 84840?

About 291.2731, exactly 2√21210.

Is 84840 divisible by 3?

Yes. Its digits add up to 24, a multiple of 3.

What is special about the number 84840?

84840 is a Harshad number: divisible by its digit sum 24.