21905933 has 24 divisors (see below), whose sum is σ = 27194880. Its totient is φ = 17246880.

The previous prime is 21905929. The next prime is 21905953. The reversal of 21905933 is 33950912.

It is not a de Polignac number, because 21905933 - 2² = 21905929 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21905933.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21905953) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 371258 + ... + 371316.

It is an arithmetic number, because the mean of its divisors is an integer number (1133120).

Almost surely, 2^21905933 is an apocalyptic number.

It is an amenable number.

21905933 is a deficient number, since it is larger than the sum of its proper divisors (5288947).

21905933 is an equidigital number, since it uses as much as digits as its factorization.

21905933 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185 (or 126 counting only the distinct ones).

The product of its (nonzero) digits is 7290, while the sum is 32.

The square root of 21905933 is about 4680.3774420446. The cubic root of 21905933 is about 279.8039997364.

The spelling of 21905933 in words is "twenty-one million, nine hundred five thousand, nine hundred thirty-three".