817861128 has 32 divisors (see below), whose sum is σ = 2336746560. Its totient is φ = 233674560.

The previous prime is 817861087. The next prime is 817861129. The reversal of 817861128 is 821168718.

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

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 817861128.

It is not an unprimeable number, because it can be changed into a prime (817861129) by changing a digit.

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, 2433943 + ... + 2434278.

It is an arithmetic number, because the mean of its divisors is an integer number (73023330).

Almost surely, 2^817861128 is an apocalyptic number.

It is an amenable number.

817861128 is an abundant number, since it is smaller than the sum of its proper divisors (1518885432).

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

817861128 is a wasteful number, since it uses less digits than its factorization.

817861128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4868237 (or 4868233 counting only the distinct ones).

The product of its digits is 43008, while the sum is 42.

The square root of 817861128 is about 28598.2714162937. The cubic root of 817861128 is about 935.1756475562.

The spelling of 817861128 in words is "eight hundred seventeen million, eight hundred sixty-one thousand, one hundred twenty-eight".