21804099 has 16 divisors (see below), whose sum is σ = 30205440. Its totient is φ = 13980320.

The previous prime is 21804091. The next prime is 21804109. The reversal of 21804099 is 99040812.

It is a cyclic number.

It is not a de Polignac number, because 21804099 - 2³ = 21804091 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21804091) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 7009 + ... + 9629.

It is an arithmetic number, because the mean of its divisors is an integer number (1887840).

Almost surely, 2^21804099 is an apocalyptic number.

21804099 is a deficient number, since it is larger than the sum of its proper divisors (8401341).

21804099 is a wasteful number, since it uses less digits than its factorization.

21804099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2730.

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 21804099 is about 4669.4859460116. The cubic root of 21804099 is about 279.3697516643.

The spelling of 21804099 in words is "twenty-one million, eight hundred four thousand, ninety-nine".