128805813 has 12 divisors (see below), whose sum is σ = 187519488. Its totient is φ = 85193640.

The previous prime is 128805793. The next prime is 128805827. The reversal of 128805813 is 318508821.

It is not a de Polignac number, because 128805813 - 2²¹ = 126708661 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128805863) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55203 + ... + 57488.

It is an arithmetic number, because the mean of its divisors is an integer number (15626624).

Almost surely, 2^128805813 is an apocalyptic number.

It is an amenable number.

128805813 is a deficient number, since it is larger than the sum of its proper divisors (58713675).

128805813 is a wasteful number, since it uses less digits than its factorization.

128805813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112824 (or 112821 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The square root of 128805813 is about 11349.2648660607. The cubic root of 128805813 is about 505.0237717137.

The spelling of 128805813 in words is "one hundred twenty-eight million, eight hundred five thousand, eight hundred thirteen".