21103204 has 6 divisors (see below), whose sum is σ = 36930614. Its totient is φ = 10551600.

The previous prime is 21103193. The next prime is 21103207. The reversal of 21103204 is 40230112.

It can be written as a sum of positive squares in only one way, i.e., 13704804 + 7398400 = 3702^2 + 2720^2 .

It is not an unprimeable number, because it can be changed into a prime (21103207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2637897 + ... + 2637904.

Almost surely, 2^21103204 is an apocalyptic number.

It is an amenable number.

21103204 is a deficient number, since it is larger than the sum of its proper divisors (15827410).

21103204 is a wasteful number, since it uses less digits than its factorization.

21103204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5275805 (or 5275803 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21103204 is about 4593.8223735795. The cubic root of 21103204 is about 276.3436348505.

Adding to 21103204 its reverse (40230112), we get a palindrome (61333316).

The spelling of 21103204 in words is "twenty-one million, one hundred three thousand, two hundred four".