128868913 has 4 divisors (see below), whose sum is σ = 129809700. Its totient is φ = 127928128.

The previous prime is 128868907. The next prime is 128868967. The reversal of 128868913 is 319868821.

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

It can be written as a sum of positive squares in 2 ways, for example, as 79067664 + 49801249 = 8892^2 + 7057^2 .

It is a cyclic number.

It is not a de Polignac number, because 128868913 - 2⁵ = 128868881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128868983) 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, 470188 + ... + 470461.

It is an arithmetic number, because the mean of its divisors is an integer number (32452425).

Almost surely, 2^128868913 is an apocalyptic number.

It is an amenable number.

128868913 is a deficient number, since it is larger than the sum of its proper divisors (940787).

128868913 is an equidigital number, since it uses as much as digits as its factorization.

128868913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 940786.

The product of its digits is 165888, while the sum is 46.

The square root of 128868913 is about 11352.0444414211. The cubic root of 128868913 is about 505.1062260609.

The spelling of 128868913 in words is "one hundred twenty-eight million, eight hundred sixty-eight thousand, nine hundred thirteen".