Is 133 a prime number?

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

For 133, the answer is: No, 133 is not a prime number.

The list of all positive divisors (i.e., the list of all integers that divide 133) is as follows: 1, 7, 19, 133.

For 133 to be a prime number, it would have been required that 133 has only two divisors, i.e., itself and 1.

Find out more:

What is a prime number?

As a consequence:

133 is a multiple of 1
133 is a multiple of 7
133 is a multiple of 19

For 133 to be a prime number, it would have been required that 133 has only two divisors, i.e., itself and 1.

However, 133 is a semiprime (also called biprime or 2-almost-prime), because it is the product of a two non-necessarily distinct prime numbers. Indeed, 133 = 7 x 19, where 7 and 19 are both prime numbers.

Is 133 a deficient number?

Yes, 133 is a deficient number, that is to say 133 is a natural number that is strictly larger than the sum of its proper divisors, i.e., the divisors of 133 without 133 itself (that is 1 + 7 + 19 = 27).

Parity of 133

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

Find out more:

What is an even number?

Is 133 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 133 is about 11.533.

Thus, the square root of 133 is not an integer, and therefore 133 is not a square number.

What is the square number of 133?

The square of a number (here 133) is the result of the product of this number (133) by itself (i.e., 133 × 133); the square of 133 is sometimes called "raising 133 to the power 2", or "133 squared".

The square of 133 is 17 689 because 133 × 133 = 133² = 17 689.

As a consequence, 133 is the square root of 17 689.

Number of digits of 133

133 is a number with 3 digits.

What are the multiples of 133?

The multiples of 133 are all integers evenly divisible by 133, that is all numbers such that the remainder of the division by 133 is zero. There are infinitely many multiples of 133. The smallest multiples of 133 are:

0: indeed, 0 is divisible by any natural number, and it is thus a multiple of 133 too, since 0 × 133 = 0
133: indeed, 133 is a multiple of itself, since 133 is evenly divisible by 133 (we have 133 / 133 = 1, so the remainder of this division is indeed zero)
266: indeed, 266 = 133 × 2
399: indeed, 399 = 133 × 3
532: indeed, 532 = 133 × 4
665: indeed, 665 = 133 × 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 133). 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 11.533). 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 133

Preceding numbers: …131, 132
Following numbers: 134, 135…

Nearest numbers from 133

Preceding prime number: 131
Following prime number: 137