128775866 has 4 divisors (see below), whose sum is σ = 193163802. Its totient is φ = 64387932.

The previous prime is 128775859. The next prime is 128775883. The reversal of 128775866 is 668577821.

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

It can be written as a sum of positive squares in only one way, i.e., 108264025 + 20511841 = 10405^2 + 4529^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32193965 + ... + 32193968.

Almost surely, 2^128775866 is an apocalyptic number.

128775866 is a deficient number, since it is larger than the sum of its proper divisors (64387936).

128775866 is an equidigital number, since it uses as much as digits as its factorization.

128775866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64387935.

The product of its digits is 1128960, while the sum is 50.

The square root of 128775866 is about 11347.9454528122. The cubic root of 128775866 is about 504.9846297972.

The spelling of 128775866 in words is "one hundred twenty-eight million, seven hundred seventy-five thousand, eight hundred sixty-six".