21032928 has 72 divisors (see below), whose sum is σ = 68363568. Its totient is φ = 6008832.

The previous prime is 21032903. The next prime is 21032933. The reversal of 21032928 is 82923012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3201 + ... + 7232.

It is an arithmetic number, because the mean of its divisors is an integer number (949494).

Almost surely, 2^21032928 is an apocalyptic number.

21032928 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21032928 is an abundant number, since it is smaller than the sum of its proper divisors (47330640).

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

21032928 is a wasteful number, since it uses less digits than its factorization.

21032928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10456 (or 10445 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21032928 is about 4586.1670270499. The cubic root of 21032928 is about 276.0365421056.

The spelling of 21032928 in words is "twenty-one million, thirty-two thousand, nine hundred twenty-eight".