817840394 has 32 divisors (see below), whose sum is σ = 1477232640. Its totient is φ = 331995312.

The previous prime is 817840381. The next prime is 817840421. The reversal of 817840394 is 493048718.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 20837 + ... + 45495.

It is an arithmetic number, because the mean of its divisors is an integer number (46163520).

Almost surely, 2^817840394 is an apocalyptic number.

817840394 is a deficient number, since it is larger than the sum of its proper divisors (659392246).

817840394 is a wasteful number, since it uses less digits than its factorization.

817840394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24794.

The product of its (nonzero) digits is 193536, while the sum is 44.

The square root of 817840394 is about 28597.9089095689. The cubic root of 817840394 is about 935.1677447901.

The spelling of 817840394 in words is "eight hundred seventeen million, eight hundred forty thousand, three hundred ninety-four".