21049004 has 12 divisors (see below), whose sum is σ = 37831584. Its totient is φ = 10239984.

The previous prime is 21049001. The next prime is 21049019. The reversal of 21049004 is 40094012.

It is not an unprimeable number, because it can be changed into a prime (21049001) 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 3 ways as a sum of consecutive naturals, for example, 70964 + ... + 71259.

It is an arithmetic number, because the mean of its divisors is an integer number (3152632).

Almost surely, 2^21049004 is an apocalyptic number.

It is an amenable number.

21049004 is a deficient number, since it is larger than the sum of its proper divisors (16782580).

21049004 is a wasteful number, since it uses less digits than its factorization.

21049004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142264 (or 142262 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21049004 is about 4587.9193541299. The cubic root of 21049004 is about 276.1068514375.

The spelling of 21049004 in words is "twenty-one million, forty-nine thousand, four".