817893640 has 16 divisors (see below), whose sum is σ = 1840260780. Its totient is φ = 327157440.

The previous prime is 817893619. The next prime is 817893683. The reversal of 817893640 is 46398718.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 811452196 + 6441444 = 28486^2 + 2538^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10223631 + ... + 10223710.

Almost surely, 2^817893640 is an apocalyptic number.

It is an amenable number.

817893640 is an abundant number, since it is smaller than the sum of its proper divisors (1022367140).

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

817893640 is a wasteful number, since it uses less digits than its factorization.

817893640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20447352 (or 20447348 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 46.

The square root of 817893640 is about 28598.8398366088. The cubic root of 817893640 is about 935.1880392393.

The spelling of 817893640 in words is "eight hundred seventeen million, eight hundred ninety-three thousand, six hundred forty".