2106021 has 4 divisors (see below), whose sum is σ = 2808032. Its totient is φ = 1404012.

The previous prime is 2106019. The next prime is 2106029. The reversal of 2106021 is 1206012.

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 not a de Polignac number, because 2106021 - 2¹ = 2106019 is a prime.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2105988 and 2106006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2106029) 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, 351001 + ... + 351006.

It is an arithmetic number, because the mean of its divisors is an integer number (702008).

2^2106021 is an apocalyptic number.

It is an amenable number.

2106021 is a deficient number, since it is larger than the sum of its proper divisors (702011).

2106021 is an equidigital number, since it uses as much as digits as its factorization.

2106021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 702010.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 2106021 is about 1451.2136300352. The cubic root of 2106021 is about 128.1801864981.

Subtracting from 2106021 its reverse (1206012), we obtain a palindrome (900009).

The spelling of 2106021 in words is "two million, one hundred six thousand, twenty-one".