21356368 has 20 divisors (see below), whose sum is σ = 45139968. Its totient is φ = 9707360.

The previous prime is 21356353. The next prime is 21356381. The reversal of 21356368 is 86365312.

It is a congruent number.

It is an unprimeable number.

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, 60496 + ... + 60847.

Almost surely, 2^21356368 is an apocalyptic number.

It is an amenable number.

21356368 is an abundant number, since it is smaller than the sum of its proper divisors (23783600).

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

21356368 is a wasteful number, since it uses less digits than its factorization.

21356368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121362 (or 121356 counting only the distinct ones).

The product of its digits is 25920, while the sum is 34.

The square root of 21356368 is about 4621.2950565832. The cubic root of 21356368 is about 277.4442947460. Note that the first 3 decimals are identical.

The spelling of 21356368 in words is "twenty-one million, three hundred fifty-six thousand, three hundred sixty-eight".