551305531 has 4 divisors (see below), whose sum is σ = 630063472. Its totient is φ = 472547592.

The previous prime is 551305483. The next prime is 551305549. The reversal of 551305531 is 135503155.

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

It is a cyclic number.

It is not a de Polignac number, because 551305531 - 2¹⁹ = 550781243 is a prime.

It is a super-2 number, since 2×551305531² = 607875577022383922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 551305531.

It is not an unprimeable number, because it can be changed into a prime (551305591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39378960 + ... + 39378973.

It is an arithmetic number, because the mean of its divisors is an integer number (157515868).

Almost surely, 2^551305531 is an apocalyptic number.

551305531 is a deficient number, since it is larger than the sum of its proper divisors (78757941).

551305531 is an equidigital number, since it uses as much as digits as its factorization.

551305531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78757940.

The product of its (nonzero) digits is 5625, while the sum is 28.

The square root of 551305531 is about 23479.8963157847. The cubic root of 551305531 is about 819.9690306567.

Adding to 551305531 its reverse (135503155), we get a palindrome (686808686).

The spelling of 551305531 in words is "five hundred fifty-one million, three hundred five thousand, five hundred thirty-one".