21704304 has 40 divisors (see below), whose sum is σ = 56361472. Its totient is φ = 7197120.

The previous prime is 21704303. The next prime is 21704317. The reversal of 21704304 is 40340712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21704303) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9057 + ... + 11199.

Almost surely, 2^21704304 is an apocalyptic number.

21704304 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21704304 is an abundant number, since it is smaller than the sum of its proper divisors (34657168).

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

21704304 is a wasteful number, since it uses less digits than its factorization.

21704304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2365 (or 2359 counting only the distinct ones).

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

The square root of 21704304 is about 4658.7878251751. The cubic root of 21704304 is about 278.9428847255.

The spelling of 21704304 in words is "twenty-one million, seven hundred four thousand, three hundred four".