Is 166 a prime number?

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

For 166, the answer is: No, 166 is not a prime number.

The list of all positive divisors (i.e., the list of all integers that divide 166) is as follows: 1, 2, 83, 166.

For 166 to be a prime number, it would have been required that 166 has only two divisors, i.e., itself and 1.

Find out more:

What is a prime number?

As a consequence:

166 is a multiple of 1
166 is a multiple of 2
166 is a multiple of 83

For 166 to be a prime number, it would have been required that 166 has only two divisors, i.e., itself and 1.

However, 166 is a semiprime (also called biprime or 2-almost-prime), because it is the product of a two non-necessarily distinct prime numbers. Indeed, 166 = 2 x 83, where 2 and 83 are both prime numbers.

Is 166 a deficient number?

Yes, 166 is a deficient number, that is to say 166 is a natural number that is strictly larger than the sum of its proper divisors, i.e., the divisors of 166 without 166 itself (that is 1 + 2 + 83 = 86).

Parity of 166

166 is an even number, because it is evenly divisible by 2: 166 / 2 = 83.

Find out more:

What is an even number?

Is 166 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 166 is about 12.884.

Thus, the square root of 166 is not an integer, and therefore 166 is not a square number.

What is the square number of 166?

The square of a number (here 166) is the result of the product of this number (166) by itself (i.e., 166 × 166); the square of 166 is sometimes called "raising 166 to the power 2", or "166 squared".

The square of 166 is 27 556 because 166 × 166 = 166² = 27 556.

As a consequence, 166 is the square root of 27 556.

Number of digits of 166

166 is a number with 3 digits.

What are the multiples of 166?

The multiples of 166 are all integers evenly divisible by 166, that is all numbers such that the remainder of the division by 166 is zero. There are infinitely many multiples of 166. The smallest multiples of 166 are:

0: indeed, 0 is divisible by any natural number, and it is thus a multiple of 166 too, since 0 × 166 = 0
166: indeed, 166 is a multiple of itself, since 166 is evenly divisible by 166 (we have 166 / 166 = 1, so the remainder of this division is indeed zero)
332: indeed, 332 = 166 × 2
498: indeed, 498 = 166 × 3
664: indeed, 664 = 166 × 4
830: indeed, 830 = 166 × 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 166). 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 12.884). 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 166

Preceding numbers: …164, 165
Following numbers: 167, 168…

Nearest numbers from 166

Preceding prime number: 163
Following prime number: 167