815845128 has 64 divisors (see below), whose sum is σ = 2337759360. Its totient is φ = 232421376.

The previous prime is 815845117. The next prime is 815845187. The reversal of 815845128 is 821548518.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 815845128.

It is an unprimeable number.

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 in 15 ways as a sum of consecutive naturals, for example, 52426 + ... + 66182.

It is an arithmetic number, because the mean of its divisors is an integer number (36527490).

Almost surely, 2^815845128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 815845128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1168879680).

815845128 is an abundant number, since it is smaller than the sum of its proper divisors (1521914232).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

815845128 is a wasteful number, since it uses less digits than its factorization.

815845128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14126 (or 14122 counting only the distinct ones).

The product of its digits is 102400, while the sum is 42.

The square root of 815845128 is about 28563.0027833209. The cubic root of 815845128 is about 934.4066232300.

The spelling of 815845128 in words is "eight hundred fifteen million, eight hundred forty-five thousand, one hundred twenty-eight".