21115204 has 12 divisors (see below), whose sum is σ = 40310928. Its totient is φ = 9597800.

The previous prime is 21115189. The next prime is 21115229. The reversal of 21115204 is 40251112.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 239902 + ... + 239989.

It is an arithmetic number, because the mean of its divisors is an integer number (3359244).

Almost surely, 2^21115204 is an apocalyptic number.

It is an amenable number.

21115204 is a deficient number, since it is larger than the sum of its proper divisors (19195724).

21115204 is a wasteful number, since it uses less digits than its factorization.

21115204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479906 (or 479904 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 21115204 is about 4595.1282898304. The cubic root of 21115204 is about 276.3960043906.

Adding to 21115204 its reverse (40251112), we get a palindrome (61366316).

The spelling of 21115204 in words is "twenty-one million, one hundred fifteen thousand, two hundred four".