2105561 has 4 divisors (see below), whose sum is σ = 2216400. Its totient is φ = 1994724.

The previous prime is 2105557. The next prime is 2105567. The reversal of 2105561 is 1655012.

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 2105561 - 2² = 2105557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2105567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55391 + ... + 55428.

It is an arithmetic number, because the mean of its divisors is an integer number (554100).

2^2105561 is an apocalyptic number.

It is an amenable number.

2105561 is a deficient number, since it is larger than the sum of its proper divisors (110839).

2105561 is a wasteful number, since it uses less digits than its factorization.

2105561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110838.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 2105561 is about 1451.0551333426. The cubic root of 2105561 is about 128.1708533877.

The spelling of 2105561 in words is "two million, one hundred five thousand, five hundred sixty-one".