128923785 has 16 divisors (see below), whose sum is σ = 229198080. Its totient is φ = 68759280.

The previous prime is 128923703. The next prime is 128923789. The reversal of 128923785 is 587329821.

It is a happy number.

It is not a de Polignac number, because 128923785 - 2⁷ = 128923657 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 128923785.

It is not an unprimeable number, because it can be changed into a prime (128923789) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 477361 + ... + 477630.

It is an arithmetic number, because the mean of its divisors is an integer number (14324880).

Almost surely, 2^128923785 is an apocalyptic number.

128923785 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

128923785 is a deficient number, since it is larger than the sum of its proper divisors (100274295).

128923785 is an equidigital number, since it uses as much as digits as its factorization.

128923785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 955005 (or 954999 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 128923785 is about 11354.4610175913. The cubic root of 128923785 is about 505.1779067978.

The spelling of 128923785 in words is "one hundred twenty-eight million, nine hundred twenty-three thousand, seven hundred eighty-five".