21045938 has 16 divisors (see below), whose sum is σ = 32967000. Its totient is φ = 10063872.

The previous prime is 21045917. The next prime is 21045961. The reversal of 21045938 is 83954012.

It can be written as a sum of positive squares in 4 ways, for example, as 18774889 + 2271049 = 4333^2 + 1507^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4658 + ... + 7986.

Almost surely, 2^21045938 is an apocalyptic number.

21045938 is a deficient number, since it is larger than the sum of its proper divisors (11921062).

21045938 is a wasteful number, since it uses less digits than its factorization.

21045938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3469.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 21045938 is about 4587.5852035684. The cubic root of 21045938 is about 276.0934448695.

The spelling of 21045938 in words is "twenty-one million, forty-five thousand, nine hundred thirty-eight".