The number 25740

Q: Is 25740 a prime number?

No. 25740 = 2^2 × 3^2 × 5 × 11 × 13, so it is divisible by 2.

25740 is a composite number with 72 divisors. Its prime factorisation is $2^{2}$ × $3^{2}$ × 5 × 11 × 13. Divisors (72): 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 15, 18, 20, 22, 26 … 25740.

Number

Pick any whole number from 1 to 100,000.

25740 = 2^{2} \times 3^{2} \times 5 \times 11 \times 13

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How to work it out

1
What is special about 25740: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.
2
25740 is composite. Its prime factorisation is
$25740 = 2^{2} \times 3^{2} \times 5 \times 11 \times 13$
3
The divisors add up to 91728; without 25740 itself that is 65988, so 25740 is abundant (65988 is more than 25740). Euler's totient φ(25740) = 5760 numbers up to 25740 share no factor with it.
4
The digits of 25740 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 77 steps to reach 1.

LaTeX source of the formulas on this page

\[ 25740 = 2^{2} \times 3^{2} \times 5 \times 11 \times 13 \]

25740 at a glance

Property	Value
Type	composite
Number of divisors	72
Sum of divisors	91728
Euler totient φ(n)	5760
Square	662547600
Cube	17053975224000
Square root	160.436903 (= 6√715)
Digit sum / digital root	18 / 9
Collatz steps to 1	77
Scientific notation	2.574 × $10^{4}$

25740 in other forms

Form	Value
In words	twenty-five thousand seven hundred and forty
Binary (base 2)	110010010001100
Octal (base 8)	62214
Hexadecimal (base 16)	648C
Base 3	1022022100
As time	25740 seconds = 7 h 9 min 0 s

Is 25740 divisible by 2 to 12?

Divisor	Answer	Rule
2	Yes (25740 ÷ 2 = 12870)	A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8).
3	Yes (25740 ÷ 3 = 8580)	A number is divisible by 3 if the digits add up to a multiple of 3.
4	Yes (25740 ÷ 4 = 6435)	A number is divisible by 4 if the last two digits make a multiple of 4.
5	Yes (25740 ÷ 5 = 5148)	A number is divisible by 5 if the last digit is 0 or 5.
6	Yes (25740 ÷ 6 = 4290)	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	Yes (25740 ÷ 9 = 2860)	A number is divisible by 9 if the digits add up to a multiple of 9.
10	Yes (25740 ÷ 10 = 2574)	A number is divisible by 10 if the last digit is 0.
11	Yes (25740 ÷ 11 = 2340)	A number is divisible by 11 if the alternating sum of the digits is a multiple of 11.
12	Yes (25740 ÷ 12 = 2145)	A number is divisible by 12 if it is divisible by both 3 and 4.

Questions

Is 25740 a prime number?

No. 25740 = $2^{2}$ × $3^{2}$ × 5 × 11 × 13, so it is divisible by 2.

What are the factors of 25740?

1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 15, 18, 20, 22, 26, 30, 33, 36, 39, 44, 45, 52, 55, 60, 65, 66, 78, 90, 99, 110, 117, 130, 132, 143, 156, 165, 180, 195, 198, 220, 234, 260, 286, 330, 390, 396, 429, 468, 495, 572, 585, 660, 715, 780, 858, 990, 1170, 1287, 1430, 1716, 1980, 2145, 2340, 2574, 2860, 4290, 5148, 6435, 8580, 12870, 25740.

What is 25740 in binary?

110010010001100 (hexadecimal 648C, octal 62214).

What is the square root of 25740?

About 160.4369, exactly 6√715.

Is 25740 divisible by 3?

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

What is special about the number 25740?

25740 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.