21024204 has 24 divisors (see below), whose sum is σ = 49132608. Its totient is φ = 6997200.

The previous prime is 21024197. The next prime is 21024209. The reversal of 21024204 is 40242012.

It is not an unprimeable number, because it can be changed into a prime (21024209) 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 7 ways as a sum of consecutive naturals, for example, 11779 + ... + 13445.

It is an arithmetic number, because the mean of its divisors is an integer number (2047192).

Almost surely, 2^21024204 is an apocalyptic number.

It is an amenable number.

21024204 is an abundant number, since it is smaller than the sum of its proper divisors (28108404).

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

21024204 is a wasteful number, since it uses less digits than its factorization.

21024204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2725 (or 2723 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 21024204 is about 4585.2158073530. The cubic root of 21024204 is about 275.9983721811.

Adding to 21024204 its reverse (40242012), we get a palindrome (61266216).

The spelling of 21024204 in words is "twenty-one million, twenty-four thousand, two hundred four".