21032028 has 48 divisors (see below), whose sum is σ = 56904960. Its totient is φ = 6705072.

The previous prime is 21032023. The next prime is 21032059. The reversal of 21032028 is 82023012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a self number, because there is not a number n which added to its sum of digits gives 21032028.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21032023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1750 + ... + 6717.

It is an arithmetic number, because the mean of its divisors is an integer number (1185520).

Almost surely, 2^21032028 is an apocalyptic number.

It is an amenable number.

21032028 is an abundant number, since it is smaller than the sum of its proper divisors (35872932).

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

21032028 is a wasteful number, since it uses less digits than its factorization.

21032028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8503 (or 8495 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21032028 is about 4586.0689048465. The cubic root of 21032028 is about 276.0326048438.

The spelling of 21032028 in words is "twenty-one million, thirty-two thousand, twenty-eight".