The number 71940

Q: Is 71940 a prime number?

No. 71940 = 2^2 × 3 × 5 × 11 × 109, so it is divisible by 2.

71940 is a composite number with 48 divisors. Its prime factorisation is $2^{2}$ × 3 × 5 × 11 × 109. Divisors (48): 1, 2, 3, 4, 5, 6, 10, 11, 12, 15, 20, 22, 30, 33, 44, 55 … 71940.

Number

Pick any whole number from 1 to 100,000.

71940 = 2^{2} \times 3 \times 5 \times 11 \times 109

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How to work it out

1
71940 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
2
71940 is composite. Its prime factorisation is
$71940 = 2^{2} \times 3 \times 5 \times 11 \times 109$
3
The divisors add up to 221760; without 71940 itself that is 149820, so 71940 is abundant (149820 is more than 71940). Euler's totient φ(71940) = 17280 numbers up to 71940 share no factor with it.
4
The digits of 71940 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 81 steps to reach 1.

LaTeX source of the formulas on this page

\[ 71940 = 2^{2} \times 3 \times 5 \times 11 \times 109 \]

71940 at a glance

Property	Value
Type	composite
Number of divisors	48
Sum of divisors	221760
Euler totient φ(n)	17280
Square	5175363600
Cube	372315657384000
Square root	268.216331 (= 2√17985)
Digit sum / digital root	21 / 3
Collatz steps to 1	81
Scientific notation	7.194 × $10^{4}$

71940 in other forms

Form	Value
In words	seventy-one thousand nine hundred and forty
Binary (base 2)	10001100100000100
Octal (base 8)	214404
Hexadecimal (base 16)	11904
Base 3	10122200110
As time	71940 seconds = 19 h 59 min 0 s

Is 71940 divisible by 2 to 12?

Divisor	Answer	Rule
2	Yes (71940 ÷ 2 = 35970)	A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8).
3	Yes (71940 ÷ 3 = 23980)	A number is divisible by 3 if the digits add up to a multiple of 3.
4	Yes (71940 ÷ 4 = 17985)	A number is divisible by 4 if the last two digits make a multiple of 4.
5	Yes (71940 ÷ 5 = 14388)	A number is divisible by 5 if the last digit is 0 or 5.
6	Yes (71940 ÷ 6 = 11990)	A number is divisible by 6 if it is divisible by both 2 and 3.
7	No (remainder 1)	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	No (remainder 3)	A number is divisible by 9 if the digits add up to a multiple of 9.
10	Yes (71940 ÷ 10 = 7194)	A number is divisible by 10 if the last digit is 0.
11	Yes (71940 ÷ 11 = 6540)	A number is divisible by 11 if the alternating sum of the digits is a multiple of 11.
12	Yes (71940 ÷ 12 = 5995)	A number is divisible by 12 if it is divisible by both 3 and 4.

Questions

Is 71940 a prime number?

No. 71940 = $2^{2}$ × 3 × 5 × 11 × 109, so it is divisible by 2.

What are the factors of 71940?

1, 2, 3, 4, 5, 6, 10, 11, 12, 15, 20, 22, 30, 33, 44, 55, 60, 66, 109, 110, 132, 165, 218, 220, 327, 330, 436, 545, 654, 660, 1090, 1199, 1308, 1635, 2180, 2398, 3270, 3597, 4796, 5995, 6540, 7194, 11990, 14388, 17985, 23980, 35970, 71940.

What is 71940 in binary?

10001100100000100 (hexadecimal 11904, octal 214404).

What is the square root of 71940?

About 268.2163, exactly 2√17985.

Is 71940 divisible by 3?

Yes. Its digits add up to 21, a multiple of 3.

What is special about the number 71940?

It is a composite number with 48 divisors.