21128132064 has 96 divisors (see below), whose sum is σ = 60447510144. Its totient is φ = 6422607360.

The previous prime is 21128132041. The next prime is 21128132093. The reversal of 21128132064 is 46023182112.

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 (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1599 + ... + 205569.

It is an arithmetic number, because the mean of its divisors is an integer number (629661564).

Almost surely, 2^21128132064 is an apocalyptic number.

21128132064 is a gapful number since it is divisible by the number (24) 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 21128132064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30223755072).

21128132064 is an abundant number, since it is smaller than the sum of its proper divisors (39319378080).

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

21128132064 is a wasteful number, since it uses less digits than its factorization.

21128132064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204080 (or 204072 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The spelling of 21128132064 in words is "twenty-one billion, one hundred twenty-eight million, one hundred thirty-two thousand, sixty-four".