20923839 has 10 divisors (see below), whose sum is σ = 31256720. Its totient is φ = 13949172.

The previous prime is 20923829. The next prime is 20923841. The reversal of 20923839 is 93832902.

It is not a de Polignac number, because 20923839 - 2⁴ = 20923823 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20923829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 129079 + ... + 129240.

It is an arithmetic number, because the mean of its divisors is an integer number (3125672).

Almost surely, 2^20923839 is an apocalyptic number.

20923839 is a deficient number, since it is larger than the sum of its proper divisors (10332881).

20923839 is an equidigital number, since it uses as much as digits as its factorization.

20923839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258331 (or 258322 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 20923839 is about 4574.2583005335. The cubic root of 20923839 is about 275.5584859631.

The spelling of 20923839 in words is "twenty million, nine hundred twenty-three thousand, eight hundred thirty-nine".