21047304 has 16 divisors (see below), whose sum is σ = 52618320. Its totient is φ = 7015760.

The previous prime is 21047303. The next prime is 21047317. The reversal of 21047304 is 40374012.

It is not an unprimeable number, because it can be changed into a prime (21047303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 438462 + ... + 438509.

It is an arithmetic number, because the mean of its divisors is an integer number (3288645).

Almost surely, 2^21047304 is an apocalyptic number.

21047304 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21047304 is an abundant number, since it is smaller than the sum of its proper divisors (31571016).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21047304 is a wasteful number, since it uses less digits than its factorization.

21047304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 876980 (or 876976 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 21047304 is about 4587.7340812214. The cubic root of 21047304 is about 276.0994180805.

The spelling of 21047304 in words is "twenty-one million, forty-seven thousand, three hundred four".