128994911 has 4 divisors (see below), whose sum is σ = 129243024. Its totient is φ = 128746800.

The previous prime is 128994907. The next prime is 128994917. The reversal of 128994911 is 119499821.

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 128994911 - 2² = 128994907 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 (128994917) 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, 123275 + ... + 124316.

It is an arithmetic number, because the mean of its divisors is an integer number (32310756).

Almost surely, 2^128994911 is an apocalyptic number.

128994911 is a deficient number, since it is larger than the sum of its proper divisors (248113).

128994911 is an equidigital number, since it uses as much as digits as its factorization.

128994911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248112.

The product of its digits is 46656, while the sum is 44.

The square root of 128994911 is about 11357.5926586579. The cubic root of 128994911 is about 505.2707903005.

The spelling of 128994911 in words is "one hundred twenty-eight million, nine hundred ninety-four thousand, nine hundred eleven".