21304608 has 96 divisors (see below), whose sum is σ = 61782336. Its totient is φ = 6386688.

The previous prime is 21304603. The next prime is 21304627. The reversal of 21304608 is 80640312.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (21304603) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53466 + ... + 53862.

It is an arithmetic number, because the mean of its divisors is an integer number (643566).

Almost surely, 2^21304608 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21304608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30891168).

21304608 is an abundant number, since it is smaller than the sum of its proper divisors (40477728).

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

21304608 is a wasteful number, since it uses less digits than its factorization.

21304608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 466 (or 458 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 21304608 is about 4615.6914974898. The cubic root of 21304608 is about 277.2199723662.

It can be divided in two parts, 21304 and 608, that added together give a palindrome (21912).

The spelling of 21304608 in words is "twenty-one million, three hundred four thousand, six hundred eight".