128403666 has 12 divisors (see below), whose sum is σ = 278207982. Its totient is φ = 42801216.

The previous prime is 128403659. The next prime is 128403679. The reversal of 128403666 is 666304821.

It can be written as a sum of positive squares in only one way, i.e., 111830625 + 16573041 = 10575^2 + 4071^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 128403666.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3566751 + ... + 3566786.

Almost surely, 2^128403666 is an apocalyptic number.

128403666 is an abundant number, since it is smaller than the sum of its proper divisors (149804316).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128403666 is a wasteful number, since it uses less digits than its factorization.

128403666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7133545 (or 7133542 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 128403666 is about 11331.5341415009. The cubic root of 128403666 is about 504.4976424490.

The spelling of 128403666 in words is "one hundred twenty-eight million, four hundred three thousand, six hundred sixty-six".