21324204 has 36 divisors (see below), whose sum is σ = 58804200. Its totient is φ = 6461760.

The previous prime is 21324203. The next prime is 21324221. The reversal of 21324204 is 40242312.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-3 number, since 3×21324204³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21324203) 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 11 ways as a sum of consecutive naturals, for example, 26529 + ... + 27320.

It is an arithmetic number, because the mean of its divisors is an integer number (1633450).

Almost surely, 2^21324204 is an apocalyptic number.

It is an amenable number.

21324204 is an abundant number, since it is smaller than the sum of its proper divisors (37479996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21324204 is a wasteful number, since it uses less digits than its factorization.

21324204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53870 (or 53865 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 21324204 is about 4617.8137684406. The cubic root of 21324204 is about 277.3049420568.

Adding to 21324204 its reverse (40242312), we get a palindrome (61566516).

It can be divided in two parts, 21324 and 204, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 21324204 in words is "twenty-one million, three hundred twenty-four thousand, two hundred four".