21073904 has 10 divisors (see below), whose sum is σ = 40830720. Its totient is φ = 10536944.

The previous prime is 21073891. The next prime is 21073909. The reversal of 21073904 is 40937012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21073909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 658544 + ... + 658575.

It is an arithmetic number, because the mean of its divisors is an integer number (4083072).

Almost surely, 2^21073904 is an apocalyptic number.

It is an amenable number.

21073904 is a deficient number, since it is larger than the sum of its proper divisors (19756816).

21073904 is a wasteful number, since it uses less digits than its factorization.

21073904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1317127 (or 1317121 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 21073904 is about 4590.6322004709. The cubic root of 21073904 is about 276.2156824210.

The spelling of 21073904 in words is "twenty-one million, seventy-three thousand, nine hundred four".