128189666 has 16 divisors (see below), whose sum is σ = 212423040. Its totient is φ = 57529680.

The previous prime is 128189641. The next prime is 128189687. The reversal of 128189666 is 666981821.

It is a self number, because there is not a number n which added to its sum of digits gives 128189666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35141 + ... + 38616.

It is an arithmetic number, because the mean of its divisors is an integer number (13276440).

Almost surely, 2^128189666 is an apocalyptic number.

128189666 is a deficient number, since it is larger than the sum of its proper divisors (84233374).

128189666 is a wasteful number, since it uses less digits than its factorization.

128189666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73849.

The product of its digits is 248832, while the sum is 47.

The square root of 128189666 is about 11322.0875283668. The cubic root of 128189666 is about 504.2172181384.

The spelling of 128189666 in words is "one hundred twenty-eight million, one hundred eighty-nine thousand, six hundred sixty-six".