128821968 has 80 divisors (see below), whose sum is σ = 403396800. Its totient is φ = 39035520.

The previous prime is 128821967. The next prime is 128821991. The reversal of 128821968 is 869128821.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128821961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8803 + ... + 18306.

It is an arithmetic number, because the mean of its divisors is an integer number (5042460).

Almost surely, 2^128821968 is an apocalyptic number.

128821968 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

128821968 is an abundant number, since it is smaller than the sum of its proper divisors (274574832).

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

128821968 is a wasteful number, since it uses less digits than its factorization.

128821968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27137 (or 27125 counting only the distinct ones).

The product of its digits is 110592, while the sum is 45.

The square root of 128821968 is about 11349.9765638525. The cubic root of 128821968 is about 505.0448844202.

The spelling of 128821968 in words is "one hundred twenty-eight million, eight hundred twenty-one thousand, nine hundred sixty-eight".