128771685 has 96 divisors (see below), whose sum is σ = 273611520. Its totient is φ = 54687744.

The previous prime is 128771677. The next prime is 128771701. The reversal of 128771685 is 586177821.

It is a happy number.

It is not a de Polignac number, because 128771685 - 2³ = 128771677 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 128771685.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 744259 + ... + 744431.

It is an arithmetic number, because the mean of its divisors is an integer number (2850120).

Almost surely, 2^128771685 is an apocalyptic number.

128771685 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

128771685 is an abundant number, since it is smaller than the sum of its proper divisors (144839835).

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

128771685 is a wasteful number, since it uses less digits than its factorization.

128771685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347 (or 344 counting only the distinct ones).

The product of its digits is 188160, while the sum is 45.

The square root of 128771685 is about 11347.7612329481. The cubic root of 128771685 is about 504.9791645817.

The spelling of 128771685 in words is "one hundred twenty-eight million, seven hundred seventy-one thousand, six hundred eighty-five".