128692885 has 4 divisors (see below), whose sum is σ = 154431468. Its totient is φ = 102954304.

The previous prime is 128692877. The next prime is 128692903. The reversal of 128692885 is 588296821.

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

It can be written as a sum of positive squares in 2 ways, for example, as 63632529 + 65060356 = 7977^2 + 8066^2 .

It is a cyclic number.

It is not a de Polignac number, because 128692885 - 2³ = 128692877 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

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, 12869284 + ... + 12869293.

It is an arithmetic number, because the mean of its divisors is an integer number (38607867).

Almost surely, 2^128692885 is an apocalyptic number.

It is an amenable number.

128692885 is a deficient number, since it is larger than the sum of its proper divisors (25738583).

128692885 is an equidigital number, since it uses as much as digits as its factorization.

128692885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25738582.

The product of its digits is 552960, while the sum is 49.

The square root of 128692885 is about 11344.2886511231. The cubic root of 128692885 is about 504.8761386260.

The spelling of 128692885 in words is "one hundred twenty-eight million, six hundred ninety-two thousand, eight hundred eighty-five".