128921691984 has 40 divisors (see below), whose sum is σ = 333190748832. Its totient is φ = 42955440000.

The previous prime is 128921691979. The next prime is 128921692007. The reversal of 128921691984 is 489196129821.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 463642 + ... + 687609.

Almost surely, 2^128921691984 is an apocalyptic number.

It is an amenable number.

128921691984 is an abundant number, since it is smaller than the sum of its proper divisors (204269056848).

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

128921691984 is a wasteful number, since it uses less digits than its factorization.

128921691984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1153595 (or 1153589 counting only the distinct ones).

The product of its digits is 4478976, while the sum is 60.

The spelling of 128921691984 in words is "one hundred twenty-eight billion, nine hundred twenty-one million, six hundred ninety-one thousand, nine hundred eighty-four".