128816388 has 72 divisors (see below), whose sum is σ = 338206232. Its totient is φ = 41306112.

The previous prime is 128816381. The next prime is 128816417. The reversal of 128816388 is 883618821.

128816388 is a `hidden beast` number, since 1 + 2 + 8 + 8 + 1 + 638 + 8 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 65804544 + 63011844 = 8112^2 + 7938^2 .

It is not an unprimeable number, because it can be changed into a prime (128816381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 128706 + ... + 129702.

Almost surely, 2^128816388 is an apocalyptic number.

128816388 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128816388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169103116).

128816388 is an abundant number, since it is smaller than the sum of its proper divisors (209389844).

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

128816388 is a wasteful number, since it uses less digits than its factorization.

128816388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1141 (or 1136 counting only the distinct ones).

The product of its digits is 147456, while the sum is 45.

The square root of 128816388 is about 11349.7307457049. The cubic root of 128816388 is about 505.0375922086.

The spelling of 128816388 in words is "one hundred twenty-eight million, eight hundred sixteen thousand, three hundred eighty-eight".