128391696 has 80 divisors (see below), whose sum is σ = 369916800. Its totient is φ = 42636672.

The previous prime is 128391691. The next prime is 128391707. The reversal of 128391696 is 696193821.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (128391691) 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, 189310 + ... + 189986.

It is an arithmetic number, because the mean of its divisors is an integer number (4623960).

Almost surely, 2^128391696 is an apocalyptic number.

128391696 is a gapful number since it is divisible by the number (16) 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 128391696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (184958400).

128391696 is an abundant number, since it is smaller than the sum of its proper divisors (241525104).

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

128391696 is a wasteful number, since it uses less digits than its factorization.

128391696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1133 (or 1121 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 128391696 is about 11331.0059571073. The cubic root of 128391696 is about 504.4819652631.

It can be divided in two parts, 12839 and 1696, that added together give a triangular number (14535 = T₁₇₀).

The spelling of 128391696 in words is "one hundred twenty-eight million, three hundred ninety-one thousand, six hundred ninety-six".