Is 279 a prime number?

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

For 279, the answer is: No, 279 is not a prime number.

The list of all positive divisors (i.e., the list of all integers that divide 279) is as follows: 1, 3, 9, 31, 93, 279.

For 279 to be a prime number, it would have been required that 279 has only two divisors, i.e., itself and 1.

Find out more:

What is a prime number?

As a consequence:

279 is a multiple of 1
279 is a multiple of 3
279 is a multiple of 9
279 is a multiple of 31
279 is a multiple of 93

For 279 to be a prime number, it would have been required that 279 has only two divisors, i.e., itself and 1.

Is 279 a deficient number?

Yes, 279 is a deficient number, that is to say 279 is a natural number that is strictly larger than the sum of its proper divisors, i.e., the divisors of 279 without 279 itself (that is 1 + 3 + 9 + 31 + 93 = 137).

Parity of 279

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

Find out more:

What is an even number?

Is 279 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 279 is about 16.703.

Thus, the square root of 279 is not an integer, and therefore 279 is not a square number.

What is the square number of 279?

The square of a number (here 279) is the result of the product of this number (279) by itself (i.e., 279 × 279); the square of 279 is sometimes called "raising 279 to the power 2", or "279 squared".

The square of 279 is 77 841 because 279 × 279 = 279² = 77 841.

As a consequence, 279 is the square root of 77 841.

Number of digits of 279

279 is a number with 3 digits.

What are the multiples of 279?

The multiples of 279 are all integers evenly divisible by 279, that is all numbers such that the remainder of the division by 279 is zero. There are infinitely many multiples of 279. The smallest multiples of 279 are:

0: indeed, 0 is divisible by any natural number, and it is thus a multiple of 279 too, since 0 × 279 = 0
279: indeed, 279 is a multiple of itself, since 279 is evenly divisible by 279 (we have 279 / 279 = 1, so the remainder of this division is indeed zero)
558: indeed, 558 = 279 × 2
837: indeed, 837 = 279 × 3
1 116: indeed, 1 116 = 279 × 4
1 395: indeed, 1 395 = 279 × 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 279). 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 16.703). 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 279

Preceding numbers: …277, 278
Following numbers: 280, 281…

Nearest numbers from 279

Preceding prime number: 277
Following prime number: 281