21568328 has 16 divisors (see below), whose sum is σ = 40590780. Its totient is φ = 10744128.

The previous prime is 21568307. The next prime is 21568331. The reversal of 21568328 is 82386512.

It can be written as a sum of positive squares in 2 ways, for example, as 21548164 + 20164 = 4642^2 + 142^2 .

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, 2651 + ... + 7082.

Almost surely, 2^21568328 is an apocalyptic number.

It is an amenable number.

21568328 is a deficient number, since it is larger than the sum of its proper divisors (19022452).

21568328 is a wasteful number, since it uses less digits than its factorization.

21568328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10016 (or 10012 counting only the distinct ones).

The product of its digits is 23040, while the sum is 35.

The square root of 21568328 is about 4644.1714007991. The cubic root of 21568328 is about 278.3591445420.

The spelling of 21568328 in words is "twenty-one million, five hundred sixty-eight thousand, three hundred twenty-eight".