21039546528 has 1344 divisors, whose sum is σ = 89955194112. Its totient is φ = 4658135040.

The previous prime is 21039546509. The next prime is 21039546533. The reversal of 21039546528 is 82564593012.

21039546528 is a `hidden beast` number, since 21 + 0 + 39 + 546 + 52 + 8 = 666.

It is an unprimeable number.

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 223 ways as a sum of consecutive naturals, for example, 396972550 + ... + 396972602.

It is an arithmetic number, because the mean of its divisors is an integer number (66930948).

Almost surely, 2^21039546528 is an apocalyptic number.

21039546528 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 21039546528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44977597056).

21039546528 is an abundant number, since it is smaller than the sum of its proper divisors (68915647584).

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

21039546528 is a wasteful number, since it uses less digits than its factorization.

21039546528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 21039546528 in words is "twenty-one billion, thirty-nine million, five hundred forty-six thousand, five hundred twenty-eight".