Is 551 a prime number?

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

For 551, the answer is: No, 551 is not a prime number.

The list of all positive divisors (i.e., the list of all integers that divide 551) is as follows: 1, 19, 29, 551.

For 551 to be a prime number, it would have been required that 551 has only two divisors, i.e., itself and 1.

Find out more:

What is a prime number?

As a consequence:

551 is a multiple of 1
551 is a multiple of 19
551 is a multiple of 29

For 551 to be a prime number, it would have been required that 551 has only two divisors, i.e., itself and 1.

However, 551 is a semiprime (also called biprime or 2-almost-prime), because it is the product of a two non-necessarily distinct prime numbers. Indeed, 551 = 19 x 29, where 19 and 29 are both prime numbers.

Is 551 a deficient number?

Yes, 551 is a deficient number, that is to say 551 is a natural number that is strictly larger than the sum of its proper divisors, i.e., the divisors of 551 without 551 itself (that is 1 + 19 + 29 = 49).

Parity of 551

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

Find out more:

What is an even number?

Is 551 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 551 is about 23.473.

Thus, the square root of 551 is not an integer, and therefore 551 is not a square number.

What is the square number of 551?

The square of a number (here 551) is the result of the product of this number (551) by itself (i.e., 551 × 551); the square of 551 is sometimes called "raising 551 to the power 2", or "551 squared".

The square of 551 is 303 601 because 551 × 551 = 551² = 303 601.

As a consequence, 551 is the square root of 303 601.

Number of digits of 551

551 is a number with 3 digits.

What are the multiples of 551?

The multiples of 551 are all integers evenly divisible by 551, that is all numbers such that the remainder of the division by 551 is zero. There are infinitely many multiples of 551. The smallest multiples of 551 are:

0: indeed, 0 is divisible by any natural number, and it is thus a multiple of 551 too, since 0 × 551 = 0
551: indeed, 551 is a multiple of itself, since 551 is evenly divisible by 551 (we have 551 / 551 = 1, so the remainder of this division is indeed zero)
1 102: indeed, 1 102 = 551 × 2
1 653: indeed, 1 653 = 551 × 3
2 204: indeed, 2 204 = 551 × 4
2 755: indeed, 2 755 = 551 × 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 551). 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 23.473). 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 551

Preceding numbers: …549, 550
Following numbers: 552, 553…

Nearest numbers from 551

Preceding prime number: 547
Following prime number: 557