Is 495 a prime number?

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

For 495, the answer is: No, 495 is not a prime number.

The list of all positive divisors (i.e., the list of all integers that divide 495) is as follows: 1, 3, 5, 9, 11, 15, 33, 45, 55, 99, 165, 495.

For 495 to be a prime number, it would have been required that 495 has only two divisors, i.e., itself and 1.

Find out more:

What is a prime number?

Actually, one can immediately see that 495 cannot be prime, because 5 is one of its divisors: indeed, a number ending with 0 or 5 has necessarily 5 among its divisors. The last digit of 495 is 5, so it is divisible by 5 and is therefore not prime.

As a consequence:

495 is a multiple of 1
495 is a multiple of 3
495 is a multiple of 5
495 is a multiple of 9
495 is a multiple of 11
495 is a multiple of 15
495 is a multiple of 33
495 is a multiple of 45
495 is a multiple of 55
495 is a multiple of 99
495 is a multiple of 165

For 495 to be a prime number, it would have been required that 495 has only two divisors, i.e., itself and 1.

Is 495 a deficient number?

Yes, 495 is a deficient number, that is to say 495 is a natural number that is strictly larger than the sum of its proper divisors, i.e., the divisors of 495 without 495 itself (that is 1 + 3 + 5 + 9 + 11 + 15 + 33 + 45 + 55 + 99 + 165 = 441).

Parity of 495

495 is an odd number, because it is not evenly divisible by 2.

Find out more:

What is an even number?

Is 495 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 495 is about 22.249.

Thus, the square root of 495 is not an integer, and therefore 495 is not a square number.

What is the square number of 495?

The square of a number (here 495) is the result of the product of this number (495) by itself (i.e., 495 × 495); the square of 495 is sometimes called "raising 495 to the power 2", or "495 squared".

The square of 495 is 245 025 because 495 × 495 = 495² = 245 025.

As a consequence, 495 is the square root of 245 025.

Number of digits of 495

495 is a number with 3 digits.

What are the multiples of 495?

The multiples of 495 are all integers evenly divisible by 495, that is all numbers such that the remainder of the division by 495 is zero. There are infinitely many multiples of 495. The smallest multiples of 495 are:

0: indeed, 0 is divisible by any natural number, and it is thus a multiple of 495 too, since 0 × 495 = 0
495: indeed, 495 is a multiple of itself, since 495 is evenly divisible by 495 (we have 495 / 495 = 1, so the remainder of this division is indeed zero)
990: indeed, 990 = 495 × 2
1 485: indeed, 1 485 = 495 × 3
1 980: indeed, 1 980 = 495 × 4
2 475: indeed, 2 475 = 495 × 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 495). 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 22.249). 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 495

Preceding numbers: …493, 494
Following numbers: 496, 497…

Nearest numbers from 495

Preceding prime number: 491
Following prime number: 499