819331668 has 72 divisors (see below), whose sum is σ = 2172538368. Its totient is φ = 259858368.

The previous prime is 819331637. The next prime is 819331679. The reversal of 819331668 is 866133918.

It is a happy number.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 160605 + ... + 165627.

It is an arithmetic number, because the mean of its divisors is an integer number (30174144).

Almost surely, 2^819331668 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 819331668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1086269184).

819331668 is an abundant number, since it is smaller than the sum of its proper divisors (1353206700).

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

819331668 is a wasteful number, since it uses less digits than its factorization.

819331668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5253 (or 5248 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 819331668 is about 28623.9701648810. The cubic root of 819331668 is about 935.7358036946.

The spelling of 819331668 in words is "eight hundred nineteen million, three hundred thirty-one thousand, six hundred sixty-eight".