Is 831 a prime number?

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

For 831, the answer is: No, 831 is not a prime number.

The list of all positive divisors (i.e., the list of all integers that divide 831) is as follows: 1, 3, 277, 831.

For 831 to be a prime number, it would have been required that 831 has only two divisors, i.e., itself and 1.

Find out more:

What is a prime number?

As a consequence:

831 is a multiple of 1
831 is a multiple of 3
831 is a multiple of 277

For 831 to be a prime number, it would have been required that 831 has only two divisors, i.e., itself and 1.

However, 831 is a semiprime (also called biprime or 2-almost-prime), because it is the product of a two non-necessarily distinct prime numbers. Indeed, 831 = 3 x 277, where 3 and 277 are both prime numbers.

Is 831 a deficient number?

Yes, 831 is a deficient number, that is to say 831 is a natural number that is strictly larger than the sum of its proper divisors, i.e., the divisors of 831 without 831 itself (that is 1 + 3 + 277 = 281).

Parity of 831

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

Find out more:

What is an even number?

Is 831 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 831 is about 28.827.

Thus, the square root of 831 is not an integer, and therefore 831 is not a square number.

What is the square number of 831?

The square of a number (here 831) is the result of the product of this number (831) by itself (i.e., 831 × 831); the square of 831 is sometimes called "raising 831 to the power 2", or "831 squared".

The square of 831 is 690 561 because 831 × 831 = 831² = 690 561.

As a consequence, 831 is the square root of 690 561.

Number of digits of 831

831 is a number with 3 digits.

What are the multiples of 831?

The multiples of 831 are all integers evenly divisible by 831, that is all numbers such that the remainder of the division by 831 is zero. There are infinitely many multiples of 831. The smallest multiples of 831 are:

0: indeed, 0 is divisible by any natural number, and it is thus a multiple of 831 too, since 0 × 831 = 0
831: indeed, 831 is a multiple of itself, since 831 is evenly divisible by 831 (we have 831 / 831 = 1, so the remainder of this division is indeed zero)
1 662: indeed, 1 662 = 831 × 2
2 493: indeed, 2 493 = 831 × 3
3 324: indeed, 3 324 = 831 × 4
4 155: indeed, 4 155 = 831 × 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 831). 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 28.827). 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 831

Preceding numbers: …829, 830
Following numbers: 832, 833…

Nearest numbers from 831

Preceding prime number: 829
Following prime number: 839