5661556111 has 4 divisors (see below), whose sum is σ = 5717611224. Its totient is φ = 5605501000.

The previous prime is 5661556063. The next prime is 5661556123. The reversal of 5661556111 is 1116551665.

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 5661556111 - 2¹³ = 5661547919 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 (5661556151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28027405 + ... + 28027606.

It is an arithmetic number, because the mean of its divisors is an integer number (1429402806).

Almost surely, 2^5661556111 is an apocalyptic number.

5661556111 is a deficient number, since it is larger than the sum of its proper divisors (56055113).

5661556111 is a wasteful number, since it uses less digits than its factorization.

5661556111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56055112.

The product of its digits is 27000, while the sum is 37.

The square root of 5661556111 is about 75243.3127327605. The cubic root of 5661556111 is about 1782.2909640931.

The spelling of 5661556111 in words is "five billion, six hundred sixty-one million, five hundred fifty-six thousand, one hundred eleven".