21696528 has 80 divisors (see below), whose sum is σ = 66154496. Its totient is φ = 5996160.

The previous prime is 21696511. The next prime is 21696529. The reversal of 21696528 is 82569612.

It is not an unprimeable number, because it can be changed into a prime (21696529) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 9375 + ... + 11457.

Almost surely, 2^21696528 is an apocalyptic number.

21696528 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 21696528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33077248).

21696528 is an abundant number, since it is smaller than the sum of its proper divisors (44457968).

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

21696528 is a wasteful number, since it uses less digits than its factorization.

21696528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2132 (or 2126 counting only the distinct ones).

The product of its digits is 51840, while the sum is 39.

The square root of 21696528 is about 4657.9531985626. The cubic root of 21696528 is about 278.9095684616.

The spelling of 21696528 in words is "twenty-one million, six hundred ninety-six thousand, five hundred twenty-eight".