21128128320732 has 24 divisors (see below), whose sum is σ = 49303122105216. Its totient is φ = 7042115722608.

The previous prime is 21128128320731. The next prime is 21128128320763. The reversal of 21128128320732 is 23702382182112.

It is a super-2 number, since 2×21128128320732² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21128128320731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74066418 + ... + 74351129.

It is an arithmetic number, because the mean of its divisors is an integer number (2054296754384).

Almost surely, 2^{21128128320732} is an apocalyptic number.

It is an amenable number.

21128128320732 is an abundant number, since it is smaller than the sum of its proper divisors (28174993784484).

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

21128128320732 is a wasteful number, since it uses less digits than its factorization.

21128128320732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148429417 (or 148429415 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 42.

The spelling of 21128128320732 in words is "twenty-one trillion, one hundred twenty-eight billion, one hundred twenty-eight million, three hundred twenty thousand, seven hundred thirty-two".