21358338 has 16 divisors (see below), whose sum is σ = 42794976. Its totient is φ = 7106400.

The previous prime is 21358321. The next prime is 21358339. The reversal of 21358338 is 83385312.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21358299 and 21358308.

It is not an unprimeable number, because it can be changed into a prime (21358339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 645 + ... + 6567.

It is an arithmetic number, because the mean of its divisors is an integer number (2674686).

Almost surely, 2^21358338 is an apocalyptic number.

21358338 is an abundant number, since it is smaller than the sum of its proper divisors (21436638).

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

21358338 is a wasteful number, since it uses less digits than its factorization.

21358338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6529.

The product of its digits is 17280, while the sum is 33.

The square root of 21358338 is about 4621.5081953838. The cubic root of 21358338 is about 277.4528253547.

The spelling of 21358338 in words is "twenty-one million, three hundred fifty-eight thousand, three hundred thirty-eight".