111905561 has 4 divisors (see below), whose sum is σ = 112016400. Its totient is φ = 111794724.

The previous prime is 111905551. The next prime is 111905593. The reversal of 111905561 is 165509111.

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 111905561 - 2¹⁰ = 111904537 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 (111905551) 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, 53891 + ... + 55928.

It is an arithmetic number, because the mean of its divisors is an integer number (28004100).

Almost surely, 2^111905561 is an apocalyptic number.

It is an amenable number.

111905561 is a deficient number, since it is larger than the sum of its proper divisors (110839).

111905561 is a wasteful number, since it uses less digits than its factorization.

111905561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110838.

The product of its (nonzero) digits is 1350, while the sum is 29.

The square root of 111905561 is about 10578.5424799450. The cubic root of 111905561 is about 481.8929317460.

The spelling of 111905561 in words is "one hundred eleven million, nine hundred five thousand, five hundred sixty-one".