21339340839 has 8 divisors (see below), whose sum is σ = 31613838320. Its totient is φ = 14226227208.

The previous prime is 21339340793. The next prime is 21339340849. The reversal of 21339340839 is 93804393312.

21339340839 is a `hidden beast` number, since 213 + 393 + 40 + 8 + 3 + 9 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-21339340839 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21339340794 and 21339340803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21339340849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 395172952 + ... + 395173005.

It is an arithmetic number, because the mean of its divisors is an integer number (3951729790).

Almost surely, 2^21339340839 is an apocalyptic number.

21339340839 is a deficient number, since it is larger than the sum of its proper divisors (10274497481).

21339340839 is an equidigital number, since it uses as much as digits as its factorization.

21339340839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 790345966 (or 790345960 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 45.

The spelling of 21339340839 in words is "twenty-one billion, three hundred thirty-nine million, three hundred forty thousand, eight hundred thirty-nine".