128661684 has 12 divisors (see below), whose sum is σ = 300210624. Its totient is φ = 42887224.

The previous prime is 128661677. The next prime is 128661707. The reversal of 128661684 is 486166821.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5360892 + ... + 5360915.

It is an arithmetic number, because the mean of its divisors is an integer number (25017552).

Almost surely, 2^128661684 is an apocalyptic number.

It is an amenable number.

128661684 is an abundant number, since it is smaller than the sum of its proper divisors (171548940).

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

128661684 is a wasteful number, since it uses less digits than its factorization.

128661684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10721814 (or 10721812 counting only the distinct ones).

The product of its digits is 110592, while the sum is 42.

The square root of 128661684 is about 11342.9133823723. The cubic root of 128661684 is about 504.8353336931.

The spelling of 128661684 in words is "one hundred twenty-eight million, six hundred sixty-one thousand, six hundred eighty-four".