21804327 has 6 divisors (see below), whose sum is σ = 31495152. Its totient is φ = 14536212.

The previous prime is 21804283. The next prime is 21804329. The reversal of 21804327 is 72340812.

It is not a de Polignac number, because 21804327 - 2²⁰ = 20755751 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21804327.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21804329) 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 5 ways as a sum of consecutive naturals, for example, 1211343 + ... + 1211360.

It is an arithmetic number, because the mean of its divisors is an integer number (5249192).

Almost surely, 2^21804327 is an apocalyptic number.

21804327 is a deficient number, since it is larger than the sum of its proper divisors (9690825).

21804327 is a wasteful number, since it uses less digits than its factorization.

21804327 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2422709 (or 2422706 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 21804327 is about 4669.5103597701. The cubic root of 21804327 is about 279.3707254274.

The spelling of 21804327 in words is "twenty-one million, eight hundred four thousand, three hundred twenty-seven".