2105545051021 has 4 divisors (see below), whose sum is σ = 2105606191932. Its totient is φ = 2105483910112.

The previous prime is 2105545051009. The next prime is 2105545051073. The reversal of 2105545051021 is 1201505455012.

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

It can be written as a sum of positive squares in 2 ways, for example, as 813369496900 + 1292175554121 = 901870^2 + 1136739^2 .

It is a cyclic number.

It is not a de Polignac number, because 2105545051021 - 2¹¹ = 2105545048973 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 (2105545051081) 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, 30518770 + ... + 30587683.

It is an arithmetic number, because the mean of its divisors is an integer number (526401547983).

Almost surely, 2^{2105545051021} is an apocalyptic number.

It is an amenable number.

2105545051021 is a deficient number, since it is larger than the sum of its proper divisors (61140911).

2105545051021 is an equidigital number, since it uses as much as digits as its factorization.

2105545051021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61140910.

The product of its (nonzero) digits is 10000, while the sum is 31.

The spelling of 2105545051021 in words is "two trillion, one hundred five billion, five hundred forty-five million, fifty-one thousand, twenty-one".