21040204 has 6 divisors (see below), whose sum is σ = 36820364. Its totient is φ = 10520100.

The previous prime is 21040199. The next prime is 21040213. The reversal of 21040204 is 40204012.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2630022 + ... + 2630029.

Almost surely, 2^21040204 is an apocalyptic number.

It is an amenable number.

21040204 is a deficient number, since it is larger than the sum of its proper divisors (15780160).

21040204 is a wasteful number, since it uses less digits than its factorization.

21040204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5260055 (or 5260053 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 21040204 is about 4586.9602134747. The cubic root of 21040204 is about 276.0683685561.

Adding to 21040204 its reverse (40204012), we get a palindrome (61244216).

The spelling of 21040204 in words is "twenty-one million, forty thousand, two hundred four".