2021839 has 2 divisors, whose sum is σ = 2021840. Its totient is φ = 2021838.

The previous prime is 2021837. The next prime is 2021843. The reversal of 2021839 is 9381202.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2021839 - 2¹ = 2021837 is a prime.

Together with 2021837, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010919 + 1010920.

It is an arithmetic number, because the mean of its divisors is an integer number (1010920).

2^2021839 is an apocalyptic number.

2021839 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021839 is an equidigital number, since it uses as much as digits as its factorization.

2021839 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 2021839 is about 1421.9138511176. The cubic root of 2021839 is about 126.4490361137.

The spelling of 2021839 in words is "two million, twenty-one thousand, eight hundred thirty-nine".