20931769728 has 96 divisors (see below), whose sum is σ = 60377818800. Its totient is φ = 6960522240.

The previous prime is 20931769709. The next prime is 20931769783. The reversal of 20931769728 is 82796713902.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 463413 + ... + 506571.

Almost surely, 2^20931769728 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 20931769728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30188909400).

20931769728 is an abundant number, since it is smaller than the sum of its proper divisors (39446049072).

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

20931769728 is a wasteful number, since it uses less digits than its factorization.

20931769728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43600 (or 43585 counting only the distinct ones).

The product of its (nonzero) digits is 2286144, while the sum is 54.

The spelling of 20931769728 in words is "twenty billion, nine hundred thirty-one million, seven hundred sixty-nine thousand, seven hundred twenty-eight".