128810669 has 4 divisors (see below), whose sum is σ = 138719196. Its totient is φ = 118902144.

The previous prime is 128810659. The next prime is 128810687. The reversal of 128810669 is 966018821.

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 5822569 + 122988100 = 2413^2 + 11090^2 .

It is a cyclic number.

It is not a de Polignac number, because 128810669 - 2²⁰ = 127762093 is a prime.

It is a super-2 number, since 2×128810669² = 33184376896455122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128810659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4954244 + ... + 4954269.

It is an arithmetic number, because the mean of its divisors is an integer number (34679799).

Almost surely, 2^128810669 is an apocalyptic number.

It is an amenable number.

128810669 is a deficient number, since it is larger than the sum of its proper divisors (9908527).

128810669 is an equidigital number, since it uses as much as digits as its factorization.

128810669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9908526.

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 128810669 is about 11349.4787986057. The cubic root of 128810669 is about 505.0301181266.

The spelling of 128810669 in words is "one hundred twenty-eight million, eight hundred ten thousand, six hundred sixty-nine".