21838365 has 24 divisors (see below), whose sum is σ = 38338560. Its totient is φ = 11497824.

The previous prime is 21838361. The next prime is 21838373. The reversal of 21838365 is 56383812.

21838365 is a `hidden beast` number, since 218 + 383 + 65 = 666.

It is not a de Polignac number, because 21838365 - 2² = 21838361 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21838361) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 484 + ... + 6626.

It is an arithmetic number, because the mean of its divisors is an integer number (1597440).

Almost surely, 2^21838365 is an apocalyptic number.

It is an amenable number.

21838365 is a deficient number, since it is larger than the sum of its proper divisors (16500195).

21838365 is a wasteful number, since it uses less digits than its factorization.

21838365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6233 (or 6230 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 21838365 is about 4673.1536460938. The cubic root of 21838365 is about 279.5160219224.

It can be divided in two parts, 218 and 38365, that added together give a palindrome (38583).

The spelling of 21838365 in words is "twenty-one million, eight hundred thirty-eight thousand, three hundred sixty-five".