21819933 has 12 divisors (see below), whose sum is σ = 31962528. Its totient is φ = 14341320.

The previous prime is 21819929. The next prime is 21819943. The reversal of 21819933 is 33991812.

It is not a de Polignac number, because 21819933 - 2² = 21819929 is a prime.

It is a super-2 number, since 2×21819933² = 952218952248978, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21819943) 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 11 ways as a sum of consecutive naturals, for example, 16435 + ... + 17712.

It is an arithmetic number, because the mean of its divisors is an integer number (2663544).

Almost surely, 2^21819933 is an apocalyptic number.

It is an amenable number.

21819933 is a deficient number, since it is larger than the sum of its proper divisors (10142595).

21819933 is a wasteful number, since it uses less digits than its factorization.

21819933 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34224 (or 34221 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 21819933 is about 4671.1811140224. The cubic root of 21819933 is about 279.4373608219.

The spelling of 21819933 in words is "twenty-one million, eight hundred nineteen thousand, nine hundred thirty-three".