128785391 has 12 divisors (see below), whose sum is σ = 148342896. Its totient is φ = 109522560.

The previous prime is 128785381. The next prime is 128785417. The reversal of 128785391 is 193587821.

It is a de Polignac number, because none of the positive numbers 2^k-128785391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128785331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 458171 + ... + 458451.

It is an arithmetic number, because the mean of its divisors is an integer number (12361908).

Almost surely, 2^128785391 is an apocalyptic number.

128785391 is a deficient number, since it is larger than the sum of its proper divisors (19557505).

128785391 is an frugal number, since it uses more digits than its factorization.

128785391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 802 (or 521 counting only the distinct ones).

The product of its digits is 120960, while the sum is 44.

The square root of 128785391 is about 11348.3651245455. The cubic root of 128785391 is about 504.9970800080.

The spelling of 128785391 in words is "one hundred twenty-eight million, seven hundred eighty-five thousand, three hundred ninety-one".