21804716 has 12 divisors (see below), whose sum is σ = 38318280. Its totient is φ = 10856640.

The previous prime is 21804701. The next prime is 21804719. The reversal of 21804716 is 61740812.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21804719) 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 3 ways as a sum of consecutive naturals, for example, 10346 + ... + 12273.

It is an arithmetic number, because the mean of its divisors is an integer number (3193190).

Almost surely, 2^21804716 is an apocalyptic number.

It is an amenable number.

21804716 is a deficient number, since it is larger than the sum of its proper divisors (16513564).

21804716 is a wasteful number, since it uses less digits than its factorization.

21804716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22864 (or 22862 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 21804716 is about 4669.5520127738. The cubic root of 21804716 is about 279.3723867883.

The spelling of 21804716 in words is "twenty-one million, eight hundred four thousand, seven hundred sixteen".