551611031365561 has 4 divisors (see below), whose sum is σ = 551783895997824. Its totient is φ = 551438166733300.

The previous prime is 551611031365553. The next prime is 551611031365571. The reversal of 551611031365561 is 165563130116155.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 551611031365561 - 2³ = 551611031365553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (551611031365571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86432311345 + ... + 86432317726.

It is an arithmetic number, because the mean of its divisors is an integer number (137945973999456).

Almost surely, 2^{551611031365561} is an apocalyptic number.

It is an amenable number.

551611031365561 is a deficient number, since it is larger than the sum of its proper divisors (172864632263).

551611031365561 is a wasteful number, since it uses less digits than its factorization.

551611031365561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172864632262.

The product of its (nonzero) digits is 1215000, while the sum is 49.

The spelling of 551611031365561 in words is "five hundred fifty-one trillion, six hundred eleven billion, thirty-one million, three hundred sixty-five thousand, five hundred sixty-one".