21304308 has 12 divisors (see below), whose sum is σ = 49710080. Its totient is φ = 7101432.

The previous prime is 21304291. The next prime is 21304319. The reversal of 21304308 is 80340312.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 887668 + ... + 887691.

Almost surely, 2^21304308 is an apocalyptic number.

It is an amenable number.

21304308 is an abundant number, since it is smaller than the sum of its proper divisors (28405772).

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

21304308 is a wasteful number, since it uses less digits than its factorization.

21304308 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1775366 (or 1775364 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 21304308 is about 4615.6589995363. The cubic root of 21304308 is about 277.2186711394.

It can be divided in two parts, 21304 and 308, that added together give a palindrome (21612).

The spelling of 21304308 in words is "twenty-one million, three hundred four thousand, three hundred eight".