2120561111 has 4 divisors (see below), whose sum is σ = 2160571752. Its totient is φ = 2080550472.

The previous prime is 2120561089. The next prime is 2120561129. The reversal of 2120561111 is 1111650212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2120561111 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 (2120561141) 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, 20005241 + ... + 20005346.

It is an arithmetic number, because the mean of its divisors is an integer number (540142938).

Almost surely, 2^2120561111 is an apocalyptic number.

2120561111 is a deficient number, since it is larger than the sum of its proper divisors (40010641).

2120561111 is an equidigital number, since it uses as much as digits as its factorization.

2120561111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40010640.

The product of its (nonzero) digits is 120, while the sum is 20.

The square root of 2120561111 is about 46049.5506058420. The cubic root of 2120561111 is about 1284.7449843428.

The spelling of 2120561111 in words is "two billion, one hundred twenty million, five hundred sixty-one thousand, one hundred eleven".