551342021 has 4 divisors (see below), whose sum is σ = 552652044. Its totient is φ = 550032000.

The previous prime is 551342009. The next prime is 551342053. The reversal of 551342021 is 120243155.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 191822500 + 359519521 = 13850^2 + 18961^2 .

It is a cyclic number.

It is not a de Polignac number, because 551342021 - 2¹⁸ = 551079877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (551372021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 654380 + ... + 655221.

It is an arithmetic number, because the mean of its divisors is an integer number (138163011).

Almost surely, 2^551342021 is an apocalyptic number.

It is an amenable number.

551342021 is a deficient number, since it is larger than the sum of its proper divisors (1310023).

551342021 is a wasteful number, since it uses less digits than its factorization.

551342021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1310022.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 551342021 is about 23480.6733506516. The cubic root of 551342021 is about 819.9871210549.

Adding to 551342021 its reverse (120243155), we get a palindrome (671585176).

The spelling of 551342021 in words is "five hundred fifty-one million, three hundred forty-two thousand, twenty-one".