128905667785 has 8 divisors (see below), whose sum is σ = 154840114440. Its totient is φ = 103022325504.

The previous prime is 128905667753. The next prime is 128905667837. The reversal of 128905667785 is 587766509821.

It can be written as a sum of positive squares in 4 ways, for example, as 3693722176 + 125211945609 = 60776^2 + 353853^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 128905667785 - 2⁵ = 128905667753 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12770542 + ... + 12780631.

It is an arithmetic number, because the mean of its divisors is an integer number (19355014305).

Almost surely, 2^128905667785 is an apocalyptic number.

It is an amenable number.

128905667785 is a deficient number, since it is larger than the sum of its proper divisors (25934446655).

128905667785 is a wasteful number, since it uses less digits than its factorization.

128905667785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25552187.

The product of its (nonzero) digits is 50803200, while the sum is 64.

The spelling of 128905667785 in words is "one hundred twenty-eight billion, nine hundred five million, six hundred sixty-seven thousand, seven hundred eighty-five".