The number 64980

Q: Is 64980 a prime number?

No. 64980 = 2^2 × 3^2 × 5 × 19^2, so it is divisible by 2.

64980 is a triangular number: 1 + 2 + … + 360 = 64980. Its prime factorisation is $2^{2}$ × $3^{2}$ × 5 × $19^{2}$ . Divisors (54): 1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 19, 20, 30, 36, 38 … 64980.

Number

Pick any whole number from 1 to 100,000.

64980 = 2^{2} \times 3^{2} \times 5 \times 19^{2}

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How to work it out

1
What is special about 64980: a triangular number: 1 + 2 + … + 360 = 64980.
2
64980 is composite. Its prime factorisation is
$64980 = 2^{2} \times 3^{2} \times 5 \times 19^{2}$
3
The divisors add up to 208026; without 64980 itself that is 143046, so 64980 is abundant (143046 is more than 64980). Euler's totient φ(64980) = 16416 numbers up to 64980 share no factor with it.
4
The digits of 64980 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 42 steps to reach 1.

LaTeX source of the formulas on this page

\[ 64980 = 2^{2} \times 3^{2} \times 5 \times 19^{2} \]

64980 at a glance

Property	Value
Type	composite
Number of divisors	54
Sum of divisors	208026
Euler totient φ(n)	16416
Square	4222400400
Cube	274371577992000
Square root	254.911749 (= 114√5)
Digit sum / digital root	27 / 9
Collatz steps to 1	42
Scientific notation	6.498 × $10^{4}$

64980 in other forms

Form	Value
In words	sixty-four thousand nine hundred and eighty
Binary (base 2)	1111110111010100
Octal (base 8)	176724
Hexadecimal (base 16)	FDD4
Base 3	10022010200
As time	64980 seconds = 18 h 3 min 0 s

Is 64980 divisible by 2 to 12?

Divisor	Answer	Rule
2	Yes (64980 ÷ 2 = 32490)	A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8).
3	Yes (64980 ÷ 3 = 21660)	A number is divisible by 3 if the digits add up to a multiple of 3.
4	Yes (64980 ÷ 4 = 16245)	A number is divisible by 4 if the last two digits make a multiple of 4.
5	Yes (64980 ÷ 5 = 12996)	A number is divisible by 5 if the last digit is 0 or 5.
6	Yes (64980 ÷ 6 = 10830)	A number is divisible by 6 if it is divisible by both 2 and 3.
7	No (remainder 6)	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 (64980 ÷ 9 = 7220)	A number is divisible by 9 if the digits add up to a multiple of 9.
10	Yes (64980 ÷ 10 = 6498)	A number is divisible by 10 if the last digit is 0.
11	No (remainder 3)	A number is divisible by 11 if the alternating sum of the digits is a multiple of 11.
12	Yes (64980 ÷ 12 = 5415)	A number is divisible by 12 if it is divisible by both 3 and 4.

Questions

Is 64980 a prime number?

No. 64980 = $2^{2}$ × $3^{2}$ × 5 × $19^{2}$ , so it is divisible by 2.

What are the factors of 64980?

1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 19, 20, 30, 36, 38, 45, 57, 60, 76, 90, 95, 114, 171, 180, 190, 228, 285, 342, 361, 380, 570, 684, 722, 855, 1083, 1140, 1444, 1710, 1805, 2166, 3249, 3420, 3610, 4332, 5415, 6498, 7220, 10830, 12996, 16245, 21660, 32490, 64980.

What is 64980 in binary?

1111110111010100 (hexadecimal FDD4, octal 176724).

What is the square root of 64980?

About 254.9117, exactly 114√5.

Is 64980 divisible by 3?

Yes. Its digits add up to 27, a multiple of 3.

What is special about the number 64980?

64980 is a triangular number: 1 + 2 + … + 360 = 64980.