21038528 has 56 divisors (see below), whose sum is σ = 48182784. Its totient is φ = 8928000.

The previous prime is 21038519. The next prime is 21038531. The reversal of 21038528 is 82583012.

It is a tau number, because it is divible by the number of its divisors (56).

It is a self number, because there is not a number n which added to its sum of digits gives 21038528.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67493 + ... + 67803.

Almost surely, 2^21038528 is an apocalyptic number.

21038528 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21038528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24091392).

21038528 is an abundant number, since it is smaller than the sum of its proper divisors (27144256).

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

21038528 is a wasteful number, since it uses less digits than its factorization.

21038528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 481 (or 471 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 21038528 is about 4586.7775180403. Note that the first 3 decimals coincide. The cubic root of 21038528 is about 276.0610381001.

The spelling of 21038528 in words is "twenty-one million, thirty-eight thousand, five hundred twenty-eight".