128171994 has 32 divisors (see below), whose sum is σ = 259687296. Its totient is φ = 42170880.

The previous prime is 128171977. The next prime is 128172001. The reversal of 128171994 is 499171821.

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, 197779 + ... + 198425.

It is an arithmetic number, because the mean of its divisors is an integer number (8115228).

Almost surely, 2^128171994 is an apocalyptic number.

128171994 is an abundant number, since it is smaller than the sum of its proper divisors (131515302).

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

128171994 is a wasteful number, since it uses less digits than its factorization.

128171994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1030.

The product of its digits is 36288, while the sum is 42.

The square root of 128171994 is about 11321.3070800151. The cubic root of 128171994 is about 504.1940469098.

The spelling of 128171994 in words is "one hundred twenty-eight million, one hundred seventy-one thousand, nine hundred ninety-four".