21027928 has 16 divisors (see below), whose sum is σ = 39983760. Its totient is φ = 10365600.

The previous prime is 21027913. The next prime is 21027931. The reversal of 21027928 is 82972012.

It is a self number, because there is not a number n which added to its sum of digits gives 21027928.

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, 17943 + ... + 19078.

It is an arithmetic number, because the mean of its divisors is an integer number (2498985).

Almost surely, 2^21027928 is an apocalyptic number.

It is an amenable number.

21027928 is a deficient number, since it is larger than the sum of its proper divisors (18955832).

21027928 is a wasteful number, since it uses less digits than its factorization.

21027928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37098 (or 37094 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 21027928 is about 4585.6218771286. The cubic root of 21027928 is about 276.0146670074.

The spelling of 21027928 in words is "twenty-one million, twenty-seven thousand, nine hundred twenty-eight".