813945128 has 8 divisors (see below), whose sum is σ = 1526147130. Its totient is φ = 406972560.

The previous prime is 813945127. The next prime is 813945149. The reversal of 813945128 is 821549318.

It can be written as a sum of positive squares in only one way, i.e., 758561764 + 55383364 = 27542^2 + 7442^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (813945127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50871563 + ... + 50871578.

Almost surely, 2^813945128 is an apocalyptic number.

It is an amenable number.

813945128 is a deficient number, since it is larger than the sum of its proper divisors (712202002).

813945128 is a wasteful number, since it uses less digits than its factorization.

813945128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101743147 (or 101743143 counting only the distinct ones).

The product of its digits is 69120, while the sum is 41.

The square root of 813945128 is about 28529.7235878653. The cubic root of 813945128 is about 933.6806878308.

The spelling of 813945128 in words is "eight hundred thirteen million, nine hundred forty-five thousand, one hundred twenty-eight".