128786785 has 8 divisors (see below), whose sum is σ = 155186856. Its totient is φ = 102600960.

The previous prime is 128786761. The next prime is 128786831. The reversal of 128786785 is 587687821.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 36857041 + 91929744 = 6071^2 + 9588^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 128786785 - 2⁵ = 128786753 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52234 + ... + 54643.

It is an arithmetic number, because the mean of its divisors is an integer number (19398357).

Almost surely, 2^128786785 is an apocalyptic number.

It is an amenable number.

128786785 is a deficient number, since it is larger than the sum of its proper divisors (26400071).

128786785 is a wasteful number, since it uses less digits than its factorization.

128786785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107123.

The product of its digits is 1505280, while the sum is 52.

The square root of 128786785 is about 11348.4265429177. The cubic root of 128786785 is about 504.9989020660.

The spelling of 128786785 in words is "one hundred twenty-eight million, seven hundred eighty-six thousand, seven hundred eighty-five".