Is 995 a prime number?

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

For 995, the answer is: No, 995 is not a prime number.

The list of all positive divisors (i.e., the list of all integers that divide 995) is as follows: 1, 5, 199, 995.

For 995 to be a prime number, it would have been required that 995 has only two divisors, i.e., itself and 1.

Find out more:

What is a prime number?

Actually, one can immediately see that 995 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 995 is 5, so it is divisible by 5 and is therefore not prime.

As a consequence:

995 is a multiple of 1
995 is a multiple of 5
995 is a multiple of 199

For 995 to be a prime number, it would have been required that 995 has only two divisors, i.e., itself and 1.

However, 995 is a semiprime (also called biprime or 2-almost-prime), because it is the product of a two non-necessarily distinct prime numbers. Indeed, 995 = 5 x 199, where 5 and 199 are both prime numbers.

Is 995 a deficient number?

Yes, 995 is a deficient number, that is to say 995 is a natural number that is strictly larger than the sum of its proper divisors, i.e., the divisors of 995 without 995 itself (that is 1 + 5 + 199 = 205).

Parity of 995

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

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What is an even number?

Is 995 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 995 is about 31.544.

Thus, the square root of 995 is not an integer, and therefore 995 is not a square number.

What is the square number of 995?

The square of a number (here 995) is the result of the product of this number (995) by itself (i.e., 995 × 995); the square of 995 is sometimes called "raising 995 to the power 2", or "995 squared".

The square of 995 is 990 025 because 995 × 995 = 995² = 990 025.

As a consequence, 995 is the square root of 990 025.

Number of digits of 995

995 is a number with 3 digits.

What are the multiples of 995?

The multiples of 995 are all integers evenly divisible by 995, that is all numbers such that the remainder of the division by 995 is zero. There are infinitely many multiples of 995. The smallest multiples of 995 are:

0: indeed, 0 is divisible by any natural number, and it is thus a multiple of 995 too, since 0 × 995 = 0
995: indeed, 995 is a multiple of itself, since 995 is evenly divisible by 995 (we have 995 / 995 = 1, so the remainder of this division is indeed zero)
1 990: indeed, 1 990 = 995 × 2
2 985: indeed, 2 985 = 995 × 3
3 980: indeed, 3 980 = 995 × 4
4 975: indeed, 4 975 = 995 × 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 995). 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 31.544). 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 995

Preceding numbers: …993, 994
Following numbers: 996, 997…

Nearest numbers from 995

Preceding prime number: 991
Following prime number: 997