21339836 has 24 divisors (see below), whose sum is σ = 42994560. Its totient is φ = 9078192.

The previous prime is 21339821. The next prime is 21339839. The reversal of 21339836 is 63893312.

It is a junction number, because it is equal to n+sod(n) for n = 21339796 and 21339805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21339839) 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, 1151 + ... + 6633.

It is an arithmetic number, because the mean of its divisors is an integer number (1791440).

Almost surely, 2^21339836 is an apocalyptic number.

It is an amenable number.

21339836 is an abundant number, since it is smaller than the sum of its proper divisors (21654724).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21339836 is a wasteful number, since it uses less digits than its factorization.

21339836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5633 (or 5631 counting only the distinct ones).

The product of its digits is 23328, while the sum is 35.

The square root of 21339836 is about 4619.5060341989. The cubic root of 21339836 is about 277.3726862354.

The spelling of 21339836 in words is "twenty-one million, three hundred thirty-nine thousand, eight hundred thirty-six".