21032839 has 4 divisors (see below), whose sum is σ = 21056224. Its totient is φ = 21009456.

The previous prime is 21032813. The next prime is 21032857. The reversal of 21032839 is 93823012.

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

It is a cyclic number.

It is not a de Polignac number, because 21032839 - 2⁵ = 21032807 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 (21032339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10287 + ... + 12160.

It is an arithmetic number, because the mean of its divisors is an integer number (5264056).

Almost surely, 2^21032839 is an apocalyptic number.

21032839 is a deficient number, since it is larger than the sum of its proper divisors (23385).

21032839 is an equidigital number, since it uses as much as digits as its factorization.

21032839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23384.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 21032839 is about 4586.1573239478. The cubic root of 21032839 is about 276.0361527591.

The spelling of 21032839 in words is "twenty-one million, thirty-two thousand, eight hundred thirty-nine".