128688311 has 4 divisors (see below), whose sum is σ = 135461400. Its totient is φ = 121915224.

The previous prime is 128688277. The next prime is 128688319. The reversal of 128688311 is 113886821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128688311 - 2⁶ = 128688247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128688319) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3386516 + ... + 3386553.

It is an arithmetic number, because the mean of its divisors is an integer number (33865350).

Almost surely, 2^128688311 is an apocalyptic number.

128688311 is a deficient number, since it is larger than the sum of its proper divisors (6773089).

128688311 is an equidigital number, since it uses as much as digits as its factorization.

128688311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6773088.

The product of its digits is 18432, while the sum is 38.

The square root of 128688311 is about 11344.0870500891. The cubic root of 128688311 is about 504.8701571226.

The spelling of 128688311 in words is "one hundred twenty-eight million, six hundred eighty-eight thousand, three hundred eleven".