55561115561 has 4 divisors (see below), whose sum is σ = 63498417792. Its totient is φ = 47623813332.

The previous prime is 55561115537. The next prime is 55561115639. The reversal of 55561115561 is 16551116555.

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 55561115561 - 2⁶ = 55561115497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (55561115501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3968651105 + ... + 3968651118.

It is an arithmetic number, because the mean of its divisors is an integer number (15874604448).

Almost surely, 2^55561115561 is an apocalyptic number.

It is an amenable number.

55561115561 is a deficient number, since it is larger than the sum of its proper divisors (7937302231).

55561115561 is an equidigital number, since it uses as much as digits as its factorization.

55561115561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7937302230.

The product of its digits is 112500, while the sum is 41.

The spelling of 55561115561 in words is "fifty-five billion, five hundred sixty-one million, one hundred fifteen thousand, five hundred sixty-one".