128821886 has 16 divisors (see below), whose sum is σ = 211656240. Its totient is φ = 58531200.

The previous prime is 128821867. The next prime is 128821909. The reversal of 128821886 is 688128821.

It is a happy number.

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, 64340 + ... + 66311.

It is an arithmetic number, because the mean of its divisors is an integer number (13228515).

Almost surely, 2^128821886 is an apocalyptic number.

128821886 is a deficient number, since it is larger than the sum of its proper divisors (82834354).

128821886 is a wasteful number, since it uses less digits than its factorization.

128821886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130699.

The product of its digits is 98304, while the sum is 44.

The square root of 128821886 is about 11349.9729515096. The cubic root of 128821886 is about 505.0447772602.

The spelling of 128821886 in words is "one hundred twenty-eight million, eight hundred twenty-one thousand, eight hundred eighty-six".