21855933 has 16 divisors (see below), whose sum is σ = 35323200. Its totient is φ = 13245840.

The previous prime is 21855929. The next prime is 21855941. The reversal of 21855933 is 33955812.

It is not a de Polignac number, because 21855933 - 2² = 21855929 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21855913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36498 + ... + 37091.

It is an arithmetic number, because the mean of its divisors is an integer number (2207700).

Almost surely, 2^21855933 is an apocalyptic number.

It is an amenable number.

21855933 is a deficient number, since it is larger than the sum of its proper divisors (13467267).

21855933 is a wasteful number, since it uses less digits than its factorization.

21855933 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73609 (or 73603 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 21855933 is about 4675.0329410604. The cubic root of 21855933 is about 279.5909545969.

It can be divided in two parts, 2185 and 5933, that added together give a palindrome (8118).

The spelling of 21855933 in words is "twenty-one million, eight hundred fifty-five thousand, nine hundred thirty-three".