20721652028 has 48 divisors (see below), whose sum is σ = 46669314048. Its totient is φ = 7812936000.

The previous prime is 20721651983. The next prime is 20721652037. The reversal of 20721652028 is 82025612702.

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 15 ways as a sum of consecutive naturals, for example, 1075583 + ... + 1094678.

It is an arithmetic number, because the mean of its divisors is an integer number (972277376).

Almost surely, 2^20721652028 is an apocalyptic number.

20721652028 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20721652028 is an abundant number, since it is smaller than the sum of its proper divisors (25947662020).

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

20721652028 is a wasteful number, since it uses less digits than its factorization.

20721652028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2170314 (or 2170312 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 35.

The spelling of 20721652028 in words is "twenty billion, seven hundred twenty-one million, six hundred fifty-two thousand, twenty-eight".