Is 989 a prime number?

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

For 989, the answer is: No, 989 is not a prime number.

The list of all positive divisors (i.e., the list of all integers that divide 989) is as follows: 1, 23, 43, 989.

For 989 to be a prime number, it would have been required that 989 has only two divisors, i.e., itself and 1.

Find out more:

What is a prime number?

As a consequence:

989 is a multiple of 1
989 is a multiple of 23
989 is a multiple of 43

For 989 to be a prime number, it would have been required that 989 has only two divisors, i.e., itself and 1.

However, 989 is a semiprime (also called biprime or 2-almost-prime), because it is the product of a two non-necessarily distinct prime numbers. Indeed, 989 = 23 x 43, where 23 and 43 are both prime numbers.

Is 989 a deficient number?

Yes, 989 is a deficient number, that is to say 989 is a natural number that is strictly larger than the sum of its proper divisors, i.e., the divisors of 989 without 989 itself (that is 1 + 23 + 43 = 67).

Parity of 989

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

Find out more:

What is an even number?

Is 989 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 989 is about 31.448.

Thus, the square root of 989 is not an integer, and therefore 989 is not a square number.

What is the square number of 989?

The square of a number (here 989) is the result of the product of this number (989) by itself (i.e., 989 × 989); the square of 989 is sometimes called "raising 989 to the power 2", or "989 squared".

The square of 989 is 978 121 because 989 × 989 = 989² = 978 121.

As a consequence, 989 is the square root of 978 121.

Number of digits of 989

989 is a number with 3 digits.

What are the multiples of 989?

The multiples of 989 are all integers evenly divisible by 989, that is all numbers such that the remainder of the division by 989 is zero. There are infinitely many multiples of 989. The smallest multiples of 989 are:

0: indeed, 0 is divisible by any natural number, and it is thus a multiple of 989 too, since 0 × 989 = 0
989: indeed, 989 is a multiple of itself, since 989 is evenly divisible by 989 (we have 989 / 989 = 1, so the remainder of this division is indeed zero)
1 978: indeed, 1 978 = 989 × 2
2 967: indeed, 2 967 = 989 × 3
3 956: indeed, 3 956 = 989 × 4
4 945: indeed, 4 945 = 989 × 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 989). 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 31.448). 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 989

Preceding numbers: …987, 988
Following numbers: 990, 991…

Nearest numbers from 989

Preceding prime number: 983
Following prime number: 991