20529891998728 has 128 divisors (see below), whose sum is σ = 46611458150400. Its totient is φ = 8280846722304.

The previous prime is 20529891998711. The next prime is 20529891998809. The reversal of 20529891998728 is 82789919892502.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1631551525 + ... + 1631564107.

It is an arithmetic number, because the mean of its divisors is an integer number (364152016800).

Almost surely, 2^{20529891998728} is an apocalyptic number.

20529891998728 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 20529891998728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23305729075200).

20529891998728 is an abundant number, since it is smaller than the sum of its proper divisors (26081566151672).

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

20529891998728 is a wasteful number, since it uses less digits than its factorization.

20529891998728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22539 (or 22535 counting only the distinct ones).

The product of its (nonzero) digits is 940584960, while the sum is 79.

The spelling of 20529891998728 in words is "twenty trillion, five hundred twenty-nine billion, eight hundred ninety-one million, nine hundred ninety-eight thousand, seven hundred twenty-eight".