21324528 has 120 divisors (see below), whose sum is σ = 65460096. Its totient is φ = 6451200.

The previous prime is 21324509. The next prime is 21324529. The reversal of 21324528 is 82542312.

21324528 is a `hidden beast` number, since 2 + 132 + 4 + 528 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21324529) 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 23 ways as a sum of consecutive naturals, for example, 75748 + ... + 76028.

Almost surely, 2^21324528 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21324528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32730048).

21324528 is an abundant number, since it is smaller than the sum of its proper divisors (44135568).

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

21324528 is a wasteful number, since it uses less digits than its factorization.

21324528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343 (or 334 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

The square root of 21324528 is about 4617.8488498434. The cubic root of 21324528 is about 277.3063465070.

The spelling of 21324528 in words is "twenty-one million, three hundred twenty-four thousand, five hundred twenty-eight".