The number 77220

Q: Is 77220 a prime number?

No. 77220 = 2^2 × 3^3 × 5 × 11 × 13, so it is divisible by 2.

77220 is a composite number with 96 divisors. Its prime factorisation is $2^{2}$ × $3^{3}$ × 5 × 11 × 13. Divisors (96): 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 15, 18, 20, 22, 26 … 77220.

Number

Pick any whole number from 1 to 100,000.

77220 = 2^{2} \times 3^{3} \times 5 \times 11 \times 13

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How to work it out

1
What is special about 77220: a Harshad number: divisible by its digit sum 18.
2
77220 is composite. Its prime factorisation is
$77220 = 2^{2} \times 3^{3} \times 5 \times 11 \times 13$
3
The divisors add up to 282240; without 77220 itself that is 205020, so 77220 is abundant (205020 is more than 77220). Euler's totient φ(77220) = 17280 numbers up to 77220 share no factor with it.
4
The digits of 77220 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 50 steps to reach 1.

LaTeX source of the formulas on this page

\[ 77220 = 2^{2} \times 3^{3} \times 5 \times 11 \times 13 \]

77220 at a glance

Property	Value
Type	composite
Number of divisors	96
Sum of divisors	282240
Euler totient φ(n)	17280
Square	5962928400
Cube	460457331048000
Square root	277.884868 (= 6√2145)
Digit sum / digital root	18 / 9
Collatz steps to 1	50
Scientific notation	7.722 × $10^{4}$

77220 in other forms

Form	Value
In words	seventy-seven thousand two hundred and twenty
Binary (base 2)	10010110110100100
Octal (base 8)	226644
Hexadecimal (base 16)	12DA4
Base 3	10220221000
As time	77220 seconds = 21 h 27 min 0 s

Is 77220 divisible by 2 to 12?

Divisor	Answer	Rule
2	Yes (77220 ÷ 2 = 38610)	A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8).
3	Yes (77220 ÷ 3 = 25740)	A number is divisible by 3 if the digits add up to a multiple of 3.
4	Yes (77220 ÷ 4 = 19305)	A number is divisible by 4 if the last two digits make a multiple of 4.
5	Yes (77220 ÷ 5 = 15444)	A number is divisible by 5 if the last digit is 0 or 5.
6	Yes (77220 ÷ 6 = 12870)	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 4)	A number is divisible by 8 if the last three digits make a multiple of 8.
9	Yes (77220 ÷ 9 = 8580)	A number is divisible by 9 if the digits add up to a multiple of 9.
10	Yes (77220 ÷ 10 = 7722)	A number is divisible by 10 if the last digit is 0.
11	Yes (77220 ÷ 11 = 7020)	A number is divisible by 11 if the alternating sum of the digits is a multiple of 11.
12	Yes (77220 ÷ 12 = 6435)	A number is divisible by 12 if it is divisible by both 3 and 4.

Questions

Is 77220 a prime number?

No. 77220 = $2^{2}$ × $3^{3}$ × 5 × 11 × 13, so it is divisible by 2.

What are the factors of 77220?

1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 15, 18, 20, 22, 26, 27, 30, 33, 36, 39, 44, 45, 52, 54, 55, 60, 65, 66, 78, 90, 99, 108, 110, 117, 130, 132, 135, 143, 156, 165, 180, 195, 198, 220, 234, 260, 270, 286, 297, 330, 351, 390, 396, 429, 468, 495, 540, 572, 585, 594, 660, 702, 715, 780, 858, 990, 1170, 1188, 1287, 1404, 1430, 1485, 1716, 1755, 1980, 2145, 2340, 2574, 2860, 2970, 3510, 3861, 4290, 5148, 5940, 6435, 7020, 7722, 8580, 12870, 15444, 19305, 25740, 38610, 77220.

What is 77220 in binary?

10010110110100100 (hexadecimal 12DA4, octal 226644).

What is the square root of 77220?

About 277.8849, exactly 6√2145.

Is 77220 divisible by 3?

Yes. Its digits add up to 18, a multiple of 3.

What is special about the number 77220?

77220 is a Harshad number: divisible by its digit sum 18.