Is 671 a prime number?

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

For 671, the answer is: No, 671 is not a prime number.

The list of all positive divisors (i.e., the list of all integers that divide 671) is as follows: 1, 11, 61, 671.

For 671 to be a prime number, it would have been required that 671 has only two divisors, i.e., itself and 1.

Find out more:

What is a prime number?

As a consequence:

671 is a multiple of 1
671 is a multiple of 11
671 is a multiple of 61

For 671 to be a prime number, it would have been required that 671 has only two divisors, i.e., itself and 1.

However, 671 is a semiprime (also called biprime or 2-almost-prime), because it is the product of a two non-necessarily distinct prime numbers. Indeed, 671 = 11 x 61, where 11 and 61 are both prime numbers.

Is 671 a deficient number?

Yes, 671 is a deficient number, that is to say 671 is a natural number that is strictly larger than the sum of its proper divisors, i.e., the divisors of 671 without 671 itself (that is 1 + 11 + 61 = 73).

Parity of 671

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

Find out more:

What is an even number?

Is 671 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 671 is about 25.904.

Thus, the square root of 671 is not an integer, and therefore 671 is not a square number.

What is the square number of 671?

The square of a number (here 671) is the result of the product of this number (671) by itself (i.e., 671 × 671); the square of 671 is sometimes called "raising 671 to the power 2", or "671 squared".

The square of 671 is 450 241 because 671 × 671 = 671² = 450 241.

As a consequence, 671 is the square root of 450 241.

Number of digits of 671

671 is a number with 3 digits.

What are the multiples of 671?

The multiples of 671 are all integers evenly divisible by 671, that is all numbers such that the remainder of the division by 671 is zero. There are infinitely many multiples of 671. The smallest multiples of 671 are:

0: indeed, 0 is divisible by any natural number, and it is thus a multiple of 671 too, since 0 × 671 = 0
671: indeed, 671 is a multiple of itself, since 671 is evenly divisible by 671 (we have 671 / 671 = 1, so the remainder of this division is indeed zero)
1 342: indeed, 1 342 = 671 × 2
2 013: indeed, 2 013 = 671 × 3
2 684: indeed, 2 684 = 671 × 4
3 355: indeed, 3 355 = 671 × 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 671). 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 25.904). 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 671

Preceding numbers: …669, 670
Following numbers: 672, 673…

Nearest numbers from 671

Preceding prime number: 661
Following prime number: 673