21804305 has 8 divisors (see below), whose sum is σ = 27542400. Its totient is φ = 16525296.

The previous prime is 21804283. The next prime is 21804329. The reversal of 21804305 is 50340812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21804305 - 2⁶ = 21804241 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 114665 + ... + 114854.

It is an arithmetic number, because the mean of its divisors is an integer number (3442800).

Almost surely, 2^21804305 is an apocalyptic number.

It is an amenable number.

21804305 is a deficient number, since it is larger than the sum of its proper divisors (5738095).

21804305 is a wasteful number, since it uses less digits than its factorization.

21804305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229543.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21804305 is about 4669.5080040621. The cubic root of 21804305 is about 279.3706314681.

The spelling of 21804305 in words is "twenty-one million, eight hundred four thousand, three hundred five".