21804153 has 16 divisors (see below), whose sum is σ = 34974720. Its totient is φ = 11803536.

The previous prime is 21804131. The next prime is 21804179. The reversal of 21804153 is 35140812.

It is not a de Polignac number, because 21804153 - 2⁵ = 21804121 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21804113) 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 15 ways as a sum of consecutive naturals, for example, 26925 + ... + 27722.

It is an arithmetic number, because the mean of its divisors is an integer number (2185920).

Almost surely, 2^21804153 is an apocalyptic number.

It is an amenable number.

21804153 is a deficient number, since it is larger than the sum of its proper divisors (13170567).

21804153 is a wasteful number, since it uses less digits than its factorization.

21804153 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54676.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 21804153 is about 4669.4917282291. The cubic root of 21804153 is about 279.3699822931.

Adding to 21804153 its reverse (35140812), we get a palindrome (56944965).

The spelling of 21804153 in words is "twenty-one million, eight hundred four thousand, one hundred fifty-three".