2105021 has 4 divisors (see below), whose sum is σ = 2108700. Its totient is φ = 2101344.

The previous prime is 2105009. The next prime is 2105027. The reversal of 2105021 is 1205012.

2105021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 105625 + 1999396 = 325^2 + 1414^2 .

It is a cyclic number.

It is not a de Polignac number, because 2105021 - 2¹⁸ = 1842877 is a prime.

It is a super-2 number, since 2×2105021² = 8862226820882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2104993 and 2105011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2105027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 776 + ... + 2193.

It is an arithmetic number, because the mean of its divisors is an integer number (527175).

2^2105021 is an apocalyptic number.

It is an amenable number.

2105021 is a deficient number, since it is larger than the sum of its proper divisors (3679).

2105021 is an equidigital number, since it uses as much as digits as its factorization.

2105021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3678.

The product of its (nonzero) digits is 20, while the sum is 11.

The square root of 2105021 is about 1450.8690499146. The cubic root of 2105021 is about 128.1598953931.

Subtracting from 2105021 its reverse (1205012), we obtain a palindrome (900009).

The spelling of 2105021 in words is "two million, one hundred five thousand, twenty-one".