Is 664 a prime number?

It is possible to find out using mathematical methods whether a given integer is a prime number or not.

For 664, the answer is: No, 664 is not a prime number.

The list of all positive divisors (i.e., the list of all integers that divide 664) is as follows: 1, 2, 4, 8, 83, 166, 332, 664.

For 664 to be a prime number, it would have been required that 664 has only two divisors, i.e., itself and 1.

Find out more:

What is a prime number?

As a consequence:

664 is a multiple of 1
664 is a multiple of 2
664 is a multiple of 4
664 is a multiple of 8
664 is a multiple of 83
664 is a multiple of 166
664 is a multiple of 332

For 664 to be a prime number, it would have been required that 664 has only two divisors, i.e., itself and 1.

Is 664 a deficient number?

Yes, 664 is a deficient number, that is to say 664 is a natural number that is strictly larger than the sum of its proper divisors, i.e., the divisors of 664 without 664 itself (that is 1 + 2 + 4 + 8 + 83 + 166 + 332 = 596).

Parity of 664

664 is an even number, because it is evenly divisible by 2: 664 / 2 = 332.

Find out more:

What is an even number?

Is 664 a perfect square number?

A number is a perfect square (or a square number) if its square root is an integer; that is to say, it is the product of an integer with itself. Here, the square root of 664 is about 25.768.

Thus, the square root of 664 is not an integer, and therefore 664 is not a square number.

What is the square number of 664?

The square of a number (here 664) is the result of the product of this number (664) by itself (i.e., 664 × 664); the square of 664 is sometimes called "raising 664 to the power 2", or "664 squared".

The square of 664 is 440 896 because 664 × 664 = 664² = 440 896.

As a consequence, 664 is the square root of 440 896.

Number of digits of 664

664 is a number with 3 digits.

What are the multiples of 664?

The multiples of 664 are all integers evenly divisible by 664, that is all numbers such that the remainder of the division by 664 is zero. There are infinitely many multiples of 664. The smallest multiples of 664 are:

0: indeed, 0 is divisible by any natural number, and it is thus a multiple of 664 too, since 0 × 664 = 0
664: indeed, 664 is a multiple of itself, since 664 is evenly divisible by 664 (we have 664 / 664 = 1, so the remainder of this division is indeed zero)
1 328: indeed, 1 328 = 664 × 2
1 992: indeed, 1 992 = 664 × 3
2 656: indeed, 2 656 = 664 × 4
3 320: indeed, 3 320 = 664 × 5
etc.

How to determine whether an integer is a prime number?

To determine the primality of a number, several algorithms can be used. The most naive technique is to test all divisors strictly smaller to the number of which we want to determine the primality (here 664). First, we can eliminate all even numbers greater than 2 (and hence 4, 6, 8…). Then, we can stop this check when we reach the square root of the number of which we want to determine the primality (here the square root is about 25.768). Historically, the sieve of Eratosthenes (dating from the Greek mathematics) implements this technique in a relatively efficient manner.

More modern techniques include the sieve of Atkin, probabilistic algorithms, and the cyclotomic AKS test.

Numbers near 664

Preceding numbers: …662, 663
Following numbers: 665, 666…

Nearest numbers from 664

Preceding prime number: 661
Following prime number: 673